best smartphone for music?

the fact that being eligible for a phone upgrade makes me happy is, i'm convinced, final proof of my spiritual degradation. in any event, since subscribing to mog i find myself more prone to using my phone as a player, so i'm looking for input as to which of the latest-and-greatest sound the best through headphones (htc one seems to be optimized for audio, but i don't know if there's really any significant difference between various brands). thanks for weighing in.
Iphone 4s.
Newer Android phone w 64 gb card, power amp music player, and high end in ear monitors. Klipsch x10 as example.
Key is getting a good music playing program for the phone that won't down sample your iTunes to mp3.

I have 250 albums of cd quality apple lossless on my 3 yr old Droid bionic w 64 g card and friends can't believe how good it sounds.

Poweramp music player costs $4.99 and plays ALAC files with all the album metadata just like iTunes.

My micro sdx cards full but they only cost $45 now, so got two more from amazon.

Works great in gym, cycling as well as syncs up in newer cars so you don't need a cd changer anymore.

I'm waiting for the S4 w 32 g internal memory to drop on price and it will be my new smartphone. I should be able to get 300 albums on it.

Cheaper than iPhone which doesn't have removable memory.
I think the OP is asking about streaming music.

FWIW I just got the latest greatest Droid Maxx. I hear no difference streaming Pandora from the 3yr old Android that it replaced.