MX Player also capable plying audio files. But I think, MX Player still lacks of feature as music player. One of them is, lyrics feature.
The lyrics can came from metadata tag from the audio file itself, or just like video subtitle (searching subtitle files in the file folder).
I hope MX Player will be able to show plain lyrics (.txt) and also lyrics with timestamp (.lrc) and common subtitles (.srt, .ass) while playing audio files.