The USB jack that HTC uses will hold a standard MiniUSB connector, it just has one notch missing to allow a custom headphone or adapter.
Basically though, Mr. Flowers is right. If you want to use your phone as a music player, make sure it either supports A2DP (bluetooth high bandwidth audio) or there is a headphone adapter.
Basically though, Mr. Flowers is right. If you want to use your phone as a music player, make sure it either supports A2DP (bluetooth high bandwidth audio) or there is a headphone adapter.