Musepack is an audio compression format with a strong emphasis on high
quality. It is not lossless, but it is designed for transparency, so
that you cannot hear differences between the original WAV file and the
much smaller MPC file.

It is based on the MPEG-1 Layer-2 / MP2 algorithms, but since 1997 it
has rapidly developed and vastly improved and is now at an advanced
stage in which it contains heavily optimized and patentless code.

Musepack is not particularly optimized for low bit rates. The encoder
was designed to be transparent at the --standard setting, thus little
low bit rate tuning has gone into the codec, unlike that of AAC,
Vorbis, WMA, and others that focus more on this region.