Best way to extract the audio from an mkv?

[Goose]

I have a bunch of concerts in mkv format that i'd like to extract the audio from, convert it to mp3 and then cut in to each song. After trying a bunch of different tools the only thing that has worked is VLC. Trouble is it only seems to work on a couple of the mkv's and not the rest despite them all having the same audio format of DTS.

If anyone knows of another tool that actually works i'd be most appreciative.

Thanks