diff --git a/src/base_media_base.h b/src/base_media_base.h
--- a/src/base_media_base.h
+++ b/src/base_media_base.h
@@ -285,11 +285,23 @@ static const uint NUM_SONGS_AVAILABLE = 
 /** Maximum number of songs in the (custom) playlist */
 static const uint NUM_SONGS_PLAYLIST  = 32;
 
+enum MusicTrackType {
+	MTT_STANDARDMIDI, ///< Standard MIDI file
+};
+
+/** Metadata about a music track. */
+struct MusicSongInfo {
+	char songname[32];       ///< name of song displayed in UI
+	byte tracknr;            ///< track number of song displayed in UI
+	const char *filename;    ///< file on disk containing song (when used in MusicSet class, this pointer is owned by MD5File object for the file)
+	MusicTrackType filetype; ///< decoder required for song file
+};
+
 /** All data of a music set. */
 struct MusicSet : BaseSet<MusicSet, NUM_SONGS_AVAILABLE, false> {
-	/** The name of the different songs. */
-	char song_name[NUM_SONGS_AVAILABLE][32];
-	byte track_nr[NUM_SONGS_AVAILABLE];
+	/** Data about individual songs in set. */
+	MusicSongInfo songinfo[NUM_SONGS_AVAILABLE];
+	/** Number of valid songs in set. */
 	byte num_available;
 
 	bool FillSetDetails(struct IniFile *ini, const char *path, const char *full_filename);