combining rock and jazz pretty much yields ska, and combining post-punk and jazz generally yields you with stuff like skunk. I use my ATH-M50's for this kind of music almost everyday, and I must say that they sound great with this kind of music. Yes, the midrange is slightly recessed, but If you have never had high quality headphones or speakers before, then I highly doubt you will be able to notice that. The bass is deep and fun, perfect for skunk, and the horn sections come in nice and clear. If you listen to bands like catch 22, streetlight manifesto, the flatliners, and dead to me, These headphones would do great by you. I suggest you read my review if these are the kind of bands you listen too, since when I wrote my review I did it in terms of these genres of music.
http://www.head-fi.org/forum/thread/386819/audio-technica-ath-m50-review