Although I don't attend masses on the regular, there's a church like this in rochester. I think they refer to themselves as the "new catholic" church. they're aren't recognized by the vatican because they go against the traditional teachings. for example, they welcome everyone to accept communion...you don't have to be catholic or have had the sacrament. they just want you to recognize the importance of it. they allow women priests and really are accepting to everyone. my aunt is gay, and has been with her partner since 1983. they were finally married in front of the church a few years ago in a more traditional catholic ceremony. the place erupted with applause when it was done. it's the only church in the area i'd consider being a part of. as you mentioned, they have no specific site, but rent an old music school and other building to hold masses.
edit: there's music, but not a real band, and the priests still wear a more traditional garb.