Mac music library app?

Solution 1:

There's not many.

Here are a couple.

Cog - http://cogx.org/
Songbird - http://getsongbird.com/

Solution 2:

I'm not using it myself at the moment, but maybe this iTunes plugin works? http://xiph.org/quicktime/

Solution 3:

The FLAC community does a good job listing resources to play these files on all OS. Have you looked over their website to see your Mac options?

Solution 4:

Stephen Booth’s Play is a great iTunes alternative that uses less memory than iTunes, and support FLAC and Ogg Vorbis out of the box. It has not been updated in some time, but it is absolutely usable. —and it’s open-source.

He has also released something more recent called Decibel. I have no experience with it, but it has the same capabilities as Play and focuses on the audiophiles. Decibel is not open-source but has support for more formats.