TXelAudio is a class which can load, save to and play WAV, MP3, AIFF, CAF, AU, FLAC, OGG VORBIS, XM, IT, S3M and MOD. It can also edit sound files (cut, fade in, fade out etc.).
It's available in OPM.
if not OpenDialog1.Execute then Exit;
a := TXelAudio.Create;
a.LoadFromFile(OpenDialog1.Filename);
a.Cut(67.5); //seconds
a.SaveToFile('output.wav');
a.SaveToFile('output.mp3', 128); //second paramater is bitrate in kbit/s. From 112 to 320 in case of mp3
a.Play;
a.Free;