diff --git a/patacrep/authors.py b/patacrep/authors.py
index 8cde76cf..83a072e3 100644
--- a/patacrep/authors.py
+++ b/patacrep/authors.py
@@ -10,6 +10,8 @@ DEFAULT_AUTHWORDS = {
     "ignore": ["unknown"],
     "sep": ["and"],
     }
+RE_AFTER = r"^.*\b{}\b(.*)$"
+RE_SEPARATOR = r"^(.*)\b *{} *(\b.*)?$"
 
 def compile_authwords(authwords):
     """Convert strings of authwords to compiled regular expressions.
@@ -23,11 +25,11 @@ def compile_authwords(authwords):
 
     # Compilation
     authwords['after'] = [
-        re.compile(r"^.*\b%s\b(.*)$" % word, re.LOCALE)
+        re.compile(RE_AFTER.format(word), re.LOCALE)
         for word in authwords['after']
         ]
     authwords['sep'] = [
-        re.compile(r"^(.*)%s +(.*)$" % word, re.LOCALE)
+        re.compile(RE_SEPARATOR.format(word), re.LOCALE)
         for word in ([" %s" % word for word in authwords['sep']] + [',', ';'])
         ]
 
@@ -37,31 +39,23 @@ def compile_authwords(authwords):
 def split_author_names(string):
     r"""Split author between first and last name.
 
-    The last space separates first and last name, but spaces following a
-    backslash or a command are not separators.
-    Examples:
-    - Edgar Allan Poe => Poe, Edgar Allan
-    - Edgar Allan \emph {Poe} => \emph {Poe}, Edgar Allan
-    - The Rolling\ Stones => Rolling\ Stones, The
-    - The {Rolling Stones} => {Rolling Stones}, The
+    The last space separates first and last name. LaTeX commands are ignored.
+
+    >>> split_author_names("Edgar Allan Poe")
+    ('Poe', 'Edgar Allan')
+    >>> split_author_names("Edgar Allan \emph {Poe}")
+    ('{Poe}', 'Edgar Allan \\emph')
+    >>> split_author_names(r"The Rolling\ Stones")
+    ('Stones', 'The Rolling\\')
+    >>> split_author_names("The {Rolling Stones}")
+    ('Stones}', 'The {Rolling')
+    >>> split_author_names("The Rolling Stones")
+    ('Rolling\xa0Stones', 'The')
+    >>> split_author_names("   John   Doe  ")
+    ('Doe', 'John')
     """
-    ignore_space = False
-    last_space = index = 0
-    brace_count = 0
-    for char in string.strip():
-        index += 1
-        if brace_count == 0:
-            if char == "\\":
-                ignore_space = True
-            elif not char.isalnum() and ignore_space:
-                ignore_space = False
-            elif char == " ":
-                last_space = index
-        if char == "}":
-            brace_count += 1
-        if char == "{":
-            brace_count -= 1
-    return string[last_space:], string[:last_space]
+    chunks = string.strip().split(" ")
+    return (chunks[-1].strip(), " ".join(chunks[:-1]).strip())
 
 
 def split_sep_author(string, sep):
@@ -71,16 +65,19 @@ def split_sep_author(string, sep):
     - string: string containing authors names ;
     - sep: regexp matching a separator.
 
-    >>> split_sep_author("Tintin and Milou", re.compile('^(.*) and (.*)$'))
+    >>> split_sep_author("Tintin and Milou", re.compile(RE_SEPARATOR.format("and")))
     ['Tintin', 'Milou']
+    >>> split_sep_author("Tintin,", re.compile(RE_SEPARATOR.format(",")))
+    ['Tintin']
     """
     authors = []
     match = sep.match(string)
     while match:
-        authors.append(match.group(2))
+        if match.group(2) is not None:
+            authors.append(match.group(2).strip())
         string = match.group(1)
         match = sep.match(string)
-    authors.insert(0, string)
+    authors.insert(0, string.strip())
     return authors
 
 ################################################################################
@@ -91,6 +88,9 @@ def processauthors_removeparen(authors_string):
     """Remove parentheses
 
     See docstring of processauthors() for more information.
+
+    >>> processauthors_removeparen("This (foo) string (bar) contains (baz) parenthesis")
+    'This  string  contains  parenthesis'
     """
     opening = 0
     dest = ""
@@ -107,6 +107,16 @@ def processauthors_split_string(authors_string, sep):
     """Split strings
 
     See docstring of processauthors() for more information.
+
+    >>> processauthors_split_string("Tintin and Milou", [re.compile(RE_SEPARATOR.format("and"))])
+    ['Tintin', 'Milou']
+    >>> processauthors_split_string("Tintin, Milou", [re.compile(RE_SEPARATOR.format(","))])
+    ['Tintin', 'Milou']
+    >>> processauthors_split_string(
+    ...     "Tintin, and Milou",
+    ...     [re.compile(RE_SEPARATOR.format(word)) for word in ['and', ',']]
+    ... )
+    ['Tintin', 'Milou']
     """
     authors_list = [authors_string]
     for sepword in sep:
@@ -160,45 +170,47 @@ def processauthors_clean_authors(authors_list):
         ]
 
 def processauthors(authors_string, after=None, ignore=None, sep=None):
-    r"""Return a list of authors
-
-    For example, we are processing:
-    # processauthors(
-    #    [
-    #        "
-    #            Lyrics by William Blake (from Milton, 1808),
-    #            music by Hubert Parry (1916),
-    #            and sung by The Royal\ Choir~of~Nowhere
-    #            (just here to show you how processing is done)
-    #        ",
-    #    ],
-    #   after = ["by"],
-    #   ignore = ["anonymous"],
-    #   sep = [re.compile('^(.*) and (.*)$')],
-    #   )
+    r"""Return an iterator of authors
+
+    For example, in the following call:
+
+    >>> set(processauthors(
+    ...   (
+    ...       "Lyrics by William Blake (from Milton, 1808), "
+    ...       "music by Hubert Parry (1916), "
+    ...       "and sung by The Royal~Choir~of~FooBar "
+    ...       "(just here to show you how processing is done)"
+    ...   ),
+    ...   **compile_authwords({
+    ...         'after': ["by"],
+    ...         'ignore': ["anonymous"],
+    ...         'sep': ["and", ","],
+    ...         })
+    ...   )) == {("Blake", "William"), ("Parry", "Hubert"), ("Royal~Choir~of~FooBar", "The")}
+    True
 
 
     The "authors_string" is processed as:
 
     1) First, parenthesis (and its content) are removed.
     # "Lyrics by William Blake, music by Hubert Parry,
-                and sung by The Royal\ Choir~of~Nowhere"
+                and sung by The Royal~Choir~of~FooBar"
 
     2) String is split, separators being comma and words from "sep".
     # ["Lyrics by William Blake", "music by Hubert Parry",
-                "sung by The Royal\ Choir~of~Nowhere"]
+                "sung by The Royal~Choir~of~FooBar"]
 
     3) Everything before words in "after" is removed.
-    # ["William Blake", "Hubert Parry", "The Royal\ Choir~of~Nowhere"]
+    # ["William Blake", "Hubert Parry", "The Royal~Choir~of~FooBar"]
 
     4) Strings containing words of "ignore" are dropped.
-    # ["William Blake", "Hubert Parry", The Royal\ Choir~of~Nowhere"]
+    # ["William Blake", "Hubert Parry", The Royal~Choir~of~FooBar"]
 
     5) First and last names are splitted
     # [
     #   ("Blake", "William"),
     #   ("Parry", "Hubert"),
-    #   ("Royal\ Choir~of~Nowhere", "The"),
+    #   ("Royal~Choir~of~FooBar", "The"),
     # ]
     """
 
@@ -209,10 +221,7 @@ def processauthors(authors_string, after=None, ignore=None, sep=None):
     if not ignore:
         ignore = []
 
-    return [
-        split_author_names(author)
-        for author
-        in processauthors_clean_authors(
+    for author in processauthors_clean_authors(
             processauthors_ignore_authors(
                 processauthors_remove_after(
                     processauthors_split_string(
@@ -222,8 +231,8 @@ def processauthors(authors_string, after=None, ignore=None, sep=None):
                         sep),
                     after),
                 ignore)
-            )
-        ]
+        ):
+        yield split_author_names(author)
 
 def process_listauthors(authors_list, after=None, ignore=None, sep=None):
     """Process a list of authors, and return the list of resulting authors."""
diff --git a/patacrep/data/examples/datadir2/img/datadir2.ly b/patacrep/data/examples/datadir2/img/datadir2.ly
new file mode 100644
index 00000000..1fd2bccb
--- /dev/null
+++ b/patacrep/data/examples/datadir2/img/datadir2.ly
@@ -0,0 +1,19 @@
+\include "_lilypond/header"
+\paper{paper-height = 6.5\cm}
+
+{
+  \key a \minor
+    \time 6/8
+    \partial 8 a'8
+    \relative c''{
+      c4 d8 e8. (f16) e8 d4 b8 g8. (a16) b8
+      c4 a8 a8. (gis16) a8 b4 gis8 e4 a8
+      c4 d8 e8. (f16 e8) d4 b8 g8. (a16) b8
+      c8. (b16) a8 gis8. (fis16) gis8 a4 a8 a4.
+
+      g'4. g8. (fis16) e8 d4 b8 g8. (a16) b8
+      c4 (a8) a8. (gis16) a8 b4 gis8 e4.
+      g'4. g8. (fis16) e8 d4 b8 g8. (a16) b8
+      c8. (b16) a8 gis8. (fis16) gis8 a4. a4.
+    }
+}
diff --git a/patacrep/data/examples/datadir2/img/datadir2.png b/patacrep/data/examples/datadir2/img/datadir2.png
new file mode 100644
index 00000000..90a75c1d
Binary files /dev/null and b/patacrep/data/examples/datadir2/img/datadir2.png differ
diff --git a/patacrep/data/examples/example-subdir.sb b/patacrep/data/examples/example-subdir.sb
index c7d23631..b1c93e9f 100644
--- a/patacrep/data/examples/example-subdir.sb
+++ b/patacrep/data/examples/example-subdir.sb
@@ -5,6 +5,7 @@
     "lilypond",
     "pictures"
   ],
+"datadir": ["datadir2"],
 "booktype" : "chorded",
 "template" : "patacrep.tex",
 "lang" : "french",
diff --git a/patacrep/data/examples/example-test.sb b/patacrep/data/examples/example-test.sb
new file mode 100644
index 00000000..4190c003
--- /dev/null
+++ b/patacrep/data/examples/example-test.sb
@@ -0,0 +1,13 @@
+{
+"bookoptions" : [
+    "diagram",
+    "repeatchords",
+    "lilypond",
+    "pictures"
+  ],
+"booktype" : "chorded",
+"template" : "patacrep.tex",
+"encoding": "utf8",
+ "content": ["tests/*.sg", "tests/*.sgc"]
+
+}
diff --git a/patacrep/data/examples/songs/subdir/datadir2.sg b/patacrep/data/examples/songs/subdir/datadir2.sg
new file mode 100644
index 00000000..f5bad860
--- /dev/null
+++ b/patacrep/data/examples/songs/subdir/datadir2.sg
@@ -0,0 +1,10 @@
+\beginsong{Image included from a different datadir\\\LaTeX}
+  [cov={datadir2}]
+
+  \cover
+
+  \lilypond{datadir2.ly}
+
+  \image{datadir2}
+
+\endsong
diff --git a/patacrep/data/examples/songs/subdir/datadir2.sgc b/patacrep/data/examples/songs/subdir/datadir2.sgc
new file mode 100644
index 00000000..b83122d4
--- /dev/null
+++ b/patacrep/data/examples/songs/subdir/datadir2.sgc
@@ -0,0 +1,6 @@
+{title : Image included from a different datadir}
+{subtitle: Chordpro}
+{cover: datadir2.png}
+
+{partition: datadir2.ly}
+{image: datadir2.png}
diff --git a/patacrep/data/examples/songs/chords.sgc b/patacrep/data/examples/songs/tests/chords.sgc
similarity index 100%
rename from patacrep/data/examples/songs/chords.sgc
rename to patacrep/data/examples/songs/tests/chords.sgc
diff --git a/patacrep/data/examples/songs/errors.sgc b/patacrep/data/examples/songs/tests/errors.sgc
similarity index 100%
rename from patacrep/data/examples/songs/errors.sgc
rename to patacrep/data/examples/songs/tests/errors.sgc
diff --git a/patacrep/data/examples/songs/tests/nolyrics.sgc b/patacrep/data/examples/songs/tests/nolyrics.sgc
new file mode 100644
index 00000000..beebbdb6
--- /dev/null
+++ b/patacrep/data/examples/songs/tests/nolyrics.sgc
@@ -0,0 +1,11 @@
+{title: No lyrics}
+{subtitle: Test of verses without any lyrics}
+
+[A]This is a [Bb]verse
+With [C#]lyrics
+
+[Adim] [Dmaj]
+[Em3]
+
+[G4]This is [Emaj3]another
+[Absus8]With lyrics
diff --git a/patacrep/songs/chordpro/ast.py b/patacrep/songs/chordpro/ast.py
index 7b331ecd..80949e10 100644
--- a/patacrep/songs/chordpro/ast.py
+++ b/patacrep/songs/chordpro/ast.py
@@ -157,6 +157,15 @@ class Verse(AST):
                     return False
         return True
 
+    @property
+    def nolyrics(self):
+        """Return `True` iff verse contains only notes (no lyrics)"""
+        for line in self.lines:
+            for item in line.line:
+                if not (isinstance(item, Space) or isinstance(item, ChordList)):
+                    return False
+        return True
+
 class Chorus(Verse):
     """Chorus"""
     type = 'chorus'
diff --git a/patacrep/songs/chordpro/data/chordpro/song_header b/patacrep/songs/chordpro/data/chordpro/song_header
index 5289d96f..ac5d8329 100644
--- a/patacrep/songs/chordpro/data/chordpro/song_header
+++ b/patacrep/songs/chordpro/data/chordpro/song_header
@@ -13,7 +13,7 @@
 (* endfor -*)
 
 (*- for author in authors -*)
-  {artist: (( author[1] ))(( author[0] ))}
+  {artist: (( author[1] )) (( author[0] ))}
 (* endfor *)
 
 (*- for key in ['album', 'copyright', 'tag'] *)
diff --git a/patacrep/songs/chordpro/data/html/song_header b/patacrep/songs/chordpro/data/html/song_header
index dbc40433..963ef686 100644
--- a/patacrep/songs/chordpro/data/html/song_header
+++ b/patacrep/songs/chordpro/data/html/song_header
@@ -7,7 +7,7 @@
 (* endfor -*)
 
 (*- for author in authors -*)
-  <h2 class="song-artist">(( author[1] ))(( author[0] ))</h2>
+  <h2 class="song-artist">(( author[1] )) (( author[0] ))</h2>
 (* endfor *)
 
 
diff --git a/patacrep/songs/chordpro/data/latex/content_verse b/patacrep/songs/chordpro/data/latex/content_verse
index 8417534f..ae3aa34f 100644
--- a/patacrep/songs/chordpro/data/latex/content_verse
+++ b/patacrep/songs/chordpro/data/latex/content_verse
@@ -2,7 +2,15 @@
   (* for line in content.lines -*)
     ((- render(line) ))
   (* endfor -*)
-(*- else -*)
+(*- elif content.nolyrics -*)
+\ifchorded
+\begin{verse*}
+  (* for line in content.lines *)
+    \musicnote {\nolyrics (( render(line) ))}
+  (* endfor *)
+\end{verse*}
+\fi
+(*- else *)
 \begin{(( content.type ))}
   (* for line in content.lines *)
     (( render(line) ))
diff --git a/patacrep/songs/chordpro/data/latex/song b/patacrep/songs/chordpro/data/latex/song
index 044ee87b..6f51d673 100644
--- a/patacrep/songs/chordpro/data/latex/song
+++ b/patacrep/songs/chordpro/data/latex/song
@@ -16,7 +16,7 @@
 }[
   by={
       (* for author in authors *)
-        (( author[1] ))(( author[0] ))
+        (( author[1] )) (( author[0] ))
         (*- if not loop.last -*)
         ,
         (* endif *)
diff --git a/test/test_authors.py b/test/test_authors.py
new file mode 100644
index 00000000..f9dfc053
--- /dev/null
+++ b/test/test_authors.py
@@ -0,0 +1,73 @@
+"""Tests of author parsing."""
+
+# pylint: disable=too-few-public-methods
+
+import unittest
+
+from patacrep import authors
+
+SPLIT_AUTHORS_DATA = [
+    ("Edgar Allan Poe", ("Poe", "Edgar Allan")),
+    ("Richard M. Stallman", ("Stallman", "Richard M.")),
+    ("Georges Brassens", ("Brassens", "Georges")),
+    ("The Who", ("Who", "The")),
+    ("Cher", ("Cher", "")),
+    ("Red~Hot~Chili~Peppers", ("Red~Hot~Chili~Peppers", "")),
+    ("The mamas~and~the~papas", ("mamas~and~the~papas", "The")),
+    ("The mamas and the papas", ("mamas and the papas", "The")), # Unbreakable spaces
+    (r"\LaTeX command", ("command", r"\LaTeX")), # LaTeX commands are ignored
+    (r"\emph{Some braces}", ("braces}", r"\emph{Some")), # LaTeX commands are ignored
+    (r"The Rolling\ Stones", ("Stones", 'The Rolling\\')), # LaTeX commands are ignored
+    ]
+
+PROCESS_AUTHORS_DATA = [
+    (
+        (
+            "Lyrics by William Blake (from Milton, 1808), music by Hubert "
+            "Parry (1916), and sung by The Royal~Choir~of~FooBar (just here to "
+            "show you how processing is done)"
+            ),
+        [
+            ("Blake", "William"),
+            ("Parry", "Hubert"),
+            ("Royal~Choir~of~FooBar", "The"),
+        ]
+    ),
+    (
+        "Anonyme (1967)",
+        [],
+    ),
+    (
+        "Lucky Luke et Jolly Jumper",
+        [
+            ("Luke", "Lucky"),
+            ("Jumper", "Jolly"),
+        ],
+    ),
+]
+
+AUTHWORDS = authors.compile_authwords({
+    "after": ["by"],
+    "ignore": ["anonymous", "Anonyme", "anonyme"],
+    "sep": ['and', 'et'],
+    })
+
+class TestAutors(unittest.TestCase):
+    """Test of author parsing."""
+
+    def test_split_author_names(self):
+        """Test of :func:`patacrep.authors.split_author_names` function."""
+        for argument, expected in SPLIT_AUTHORS_DATA:
+            with self.subTest(argument=argument, expected=expected):
+                self.assertEqual(authors.split_author_names(argument), expected)
+
+    def test_processauthors(self):
+        """Test of :func:`patacrep.authors.processauthors` function."""
+        for argument, expected in PROCESS_AUTHORS_DATA:
+            with self.subTest(argument=argument, expected=expected):
+                self.assertEqual(
+                    set(
+                        authors.processauthors(argument, **AUTHWORDS)
+                    ),
+                    set(expected)
+                    )
diff --git a/test/test_chordpro/author_names.sgc b/test/test_chordpro/author_names.sgc
index a6818f7c..36a39230 100644
--- a/test/test_chordpro/author_names.sgc
+++ b/test/test_chordpro/author_names.sgc
@@ -1,6 +1,6 @@
 {language: english}
 {title: Title}
 {artist: The Beatles}
-{artist: Oasis}
+{artist:  Oasis}
 {artist: The the beatles}
 
diff --git a/test/test_chordpro/author_names.tex b/test/test_chordpro/author_names.tex
index 123a58d3..8bf4fcfc 100644
--- a/test/test_chordpro/author_names.tex
+++ b/test/test_chordpro/author_names.tex
@@ -3,10 +3,10 @@
 \beginsong{Title}[
   by={
         The Beatles,
-        Oasis,
+         Oasis,
         The the beatles  },
 ]
 
 
 
-\endsong
\ No newline at end of file
+\endsong
diff --git a/test/test_chordpro/greensleeves.sgc b/test/test_chordpro/greensleeves.sgc
index eafed1a2..389f14d1 100644
--- a/test/test_chordpro/greensleeves.sgc
+++ b/test/test_chordpro/greensleeves.sgc
@@ -3,7 +3,7 @@
 {title: Greensleeves}
 {title: Un autre sous-titre}
 {title: Un sous titre}
-{artist: Traditionnel}
+{artist:  Traditionnel}
 {album: Angleterre}
 {cov: traditionnel}
 
diff --git a/test/test_chordpro/greensleeves.tex b/test/test_chordpro/greensleeves.tex
index f760253c..a0b602c0 100644
--- a/test/test_chordpro/greensleeves.tex
+++ b/test/test_chordpro/greensleeves.tex
@@ -5,7 +5,7 @@
 Un autre sous-titre\\
 Un sous titre}[
   by={
-        Traditionnel  },
+         Traditionnel  },
   album={Angleterre},
   cov={traditionnel},
 ]
diff --git a/test/test_chordpro/metadata.sgc b/test/test_chordpro/metadata.sgc
index 499bb833..979c1388 100644
--- a/test/test_chordpro/metadata.sgc
+++ b/test/test_chordpro/metadata.sgc
@@ -6,8 +6,8 @@
 {title: Subtitle3}
 {title: Subtitle4}
 {title: Subtitle5}
-{artist: Author1}
-{artist: Author2}
+{artist:  Author1}
+{artist:  Author2}
 {album: Album}
 {copyright: Copyright}
 {cov: Cover}
diff --git a/test/test_chordpro/metadata.tex b/test/test_chordpro/metadata.tex
index bb5393a1..fa29ec3c 100644
--- a/test/test_chordpro/metadata.tex
+++ b/test/test_chordpro/metadata.tex
@@ -7,8 +7,8 @@ Subtitle3\\
 Subtitle4\\
 Subtitle5}[
   by={
-        Author1,
-        Author2  },
+         Author1,
+         Author2  },
   album={Album},
   copyright={Copyright},
   cov={Cover},
diff --git a/test/test_chordpro/nolyrics.sgc b/test/test_chordpro/nolyrics.sgc
new file mode 100644
index 00000000..fd59c884
--- /dev/null
+++ b/test/test_chordpro/nolyrics.sgc
@@ -0,0 +1,14 @@
+{language: english}
+
+A chorus [A]with lyrics
+[Emaj3]maj et nombre
+
+
+[A B#]
+
+
+[A] [B]
+[C]
+
+
+A chorus [C]with lyrics
diff --git a/test/test_chordpro/nolyrics.source b/test/test_chordpro/nolyrics.source
new file mode 100644
index 00000000..881c1ab9
--- /dev/null
+++ b/test/test_chordpro/nolyrics.source
@@ -0,0 +1,9 @@
+A chorus [A]with lyrics
+[Emaj3]maj et nombre
+
+[A B#]
+
+[A] [B]
+[C]
+
+A chorus [C]with lyrics
diff --git a/test/test_chordpro/nolyrics.tex b/test/test_chordpro/nolyrics.tex
new file mode 100644
index 00000000..343f4e63
--- /dev/null
+++ b/test/test_chordpro/nolyrics.tex
@@ -0,0 +1,34 @@
+\selectlanguage{english}
+
+\beginsong{}[
+  by={
+  },
+]
+
+
+\begin{verse}
+    A chorus \[A]with lyrics
+    \[Emaj3]maj et nombre
+\end{verse}
+
+
+\ifchorded
+\begin{verse*}
+    \musicnote {\nolyrics \[A B#]}
+\end{verse*}
+\fi
+
+
+\ifchorded
+\begin{verse*}
+    \musicnote {\nolyrics \[A] \[B]}
+    \musicnote {\nolyrics \[C]}
+\end{verse*}
+\fi
+
+
+\begin{verse}
+    A chorus \[C]with lyrics
+\end{verse}
+
+\endsong