Monkey’s Audio(APE) is a file format for audio data compression. Being a lossless format, Monkey’s Audio does not discard data during the process of encoding, unlike lossy compression methods such as AAC, MP3, Vorbis and Musepack.
The Banshee music player comes with new installed Ubuntu 11.10 Oneiric by default doesn’t play ape files. But you can install
gstreamer0.10-ffmpeg to make it work.
Launch Ubuntu Software Center, type to search “banshee”. In its Add-ons, tick the check-box before “GStreamer ffmpeg video plugin(gstreamer0.10-ffmpeg)” and apply changes.
Finally, log-out and back in.