I've been wearing hearing aids for over 20 years, and in my experience, the best quality ones sound the best for music or anything else; hearing aids are programmable, so you can have them set at one setting/curve if you're going to be at a dinner with background conversation, for example, and a completely different setting/curve if you're listening to music. There are usually about 4 or 5 different programs the audiologist can set up for you.
I would also go with custom-molded ear-pieces if you can afford them, as the better the seal, the better the sound. I wear behind the ear ones for everything but headphones, where I've got in-ear ones.
I don't know anything about the new hearing aids you can get without an audiologist.