diff --git a/Doxyfile.in b/Doxyfile.in
index 081a315119..84330a4879 100644
--- a/Doxyfile.in
+++ b/Doxyfile.in
@@ -322,6 +322,7 @@ PREDEFINED             = WITH_ZLIB \
                          _UNICODE \
                          _GNU_SOURCE \
                          CDECL= \
+                         CALLBACK= \
                          FINAL=
 EXPAND_AS_DEFINED      = DEFINE_POOL_METHOD
 SKIP_FUNCTION_MACROS   = YES
diff --git a/src/music/dmusic.cpp b/src/music/dmusic.cpp
index c676656847..a97e128a55 100644
--- a/src/music/dmusic.cpp
+++ b/src/music/dmusic.cpp
@@ -76,23 +76,72 @@ struct DLSFile {
 	std::vector<POOLCUE> pool_cues;
 	std::vector<DLSWave> waves;
 
-	/** Try loading a DLS file into memory. */
+	/**
+	 * Try loading a DLS file into memory.
+	 * @param file The file to load.
+	 * @return \c true iff the file was loaded without issues.
+	 */
 	bool LoadFile(std::string_view file);
 
 private:
-	/** Load an articulation structure from a DLS file. */
+	/**
+	 * Load an articulation structure from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @param out The container to read the DLS articulation into.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSArticulation(FileHandle &f, DWORD list_length, std::vector<CONNECTION> &out);
-	/** Load a list of regions from a DLS file. */
+
+	/**
+	 * Load a list of regions from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @param instrument The instrument to load the region list for.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSRegionList(FileHandle &f, DWORD list_length, DLSInstrument &instrument);
-	/** Load a single region from a DLS file. */
+
+	/**
+	 * Load a single region from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @param out The container to read the DLS region into.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSRegion(FileHandle &f, DWORD list_length, std::vector<DLSRegion> &out);
-	/** Load a list of instruments from a DLS file. */
+
+	/**
+	 * Load a list of instruments from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSInstrumentList(FileHandle &f, DWORD list_length);
-	/** Load a single instrument from a DLS file. */
+
+	/**
+	 * Load a single instrument from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSInstrument(FileHandle &f, DWORD list_length);
-	/** Load a list of waves from a DLS file. */
+
+	/**
+	 * Load a list of waves from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSWaveList(FileHandle &f, DWORD list_length);
-	/** Load a single wave from a DLS file. */
+
+	/**
+	 * Load a single wave from a DLS file.
+	 * @param f The file to read the data from.
+	 * @param list_length The length of the data chunk in the file.
+	 * @param offset The offset within the file.
+	 * @return \c true iff the data was loaded without issues.
+	 */
 	bool ReadDLSWave(FileHandle &f, DWORD list_length, long offset);
 };
 
@@ -551,7 +600,12 @@ static void TransmitStandardSysex(IDirectMusicBuffer *buffer, REFERENCE_TIME rt,
 	TransmitSysex(buffer, rt, data, length);
 }
 
-/** Transmit 'Note off' messages to all MIDI channels. */
+/**
+ * Transmit 'Note off' messages to all MIDI channels.
+ * @param buffer The buffer used for MIDI music.
+ * @param block_time Timestamp of the last sent block.
+ * @param cur_time Current timestamp.
+ */
 static void TransmitNotesOff(IDirectMusicBuffer *buffer, REFERENCE_TIME block_time, REFERENCE_TIME cur_time)
 {
 	for (int ch = 0; ch < 16; ch++) {
diff --git a/src/music/midifile.cpp b/src/music/midifile.cpp
index 5087fd7883..60dffc33d2 100644
--- a/src/music/midifile.cpp
+++ b/src/music/midifile.cpp
@@ -623,6 +623,9 @@ struct MpsMachine {
 
 	/**
 	 * Play one frame of data from one channel
+	 * @param[out] outblock The block to the music to.
+	 * @param channel The channel of the block to play.
+	 * @return The new delay for playing.
 	 */
 	uint16_t PlayChannelFrame(MidiFile::DataBlock &outblock, int channel)
 	{
@@ -748,6 +751,8 @@ struct MpsMachine {
 
 	/**
 	 * Play one frame of data into a block.
+	 * @param[out] block The block to write to.
+	 * @return \c true iff there is data to play.
 	 */
 	bool PlayFrame(MidiFile::DataBlock &block)
 	{
@@ -774,6 +779,7 @@ struct MpsMachine {
 
 	/**
 	 * Perform playback of whole song.
+	 * @return Always \c true.
 	 */
 	bool PlayInto()
 	{
diff --git a/src/music/win32_m.cpp b/src/music/win32_m.cpp
index fab160a5ee..3f1bb3af02 100644
--- a/src/music/win32_m.cpp
+++ b/src/music/win32_m.cpp
@@ -105,6 +105,7 @@ static void TransmitStandardSysex(MidiSysexMessage msg)
 /**
  * Realtime MIDI playback service routine.
  * This is called by the multimedia timer.
+ * @param uTimerID The identifier of the timer.
  */
 void CALLBACK TimerCallback(UINT uTimerID, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR)
 {