I'm a member of a band, band "A", which has played together for over a year. For the past year, band "A" has been basically the only musical project for all of the members. We just started renting a house and living together primarily so that we can practice together more often and take the band more seriously. We have the keys to the house but we haven't moved in yet. Our new house has a basement that makes an ideal rehearsal space. It's in a metropolitan area so rehearsal space is very hard to come by.
I was recently offered a position in a second band, band "B". The members of band B are at best acquaintances to the members of band A, and on average, complete strangers. I accepted the position in B because I think that my schedule can handle the additional responsibility. Further, the members of A seem to be at-capacity in terms of taking on additional gigs. So since band A can't fill my desire to play more gigs, band B seems like a good opportunity for me to play more shows without having to stress the life balance of band A's members.
Band A had a mixed reaction to me joining band B. Reactions ranged from "that's fine as long as it doesn't impact band A" to "please don't join band B, band A should be your only musical project", sometimes these mixed reactions have even come from the same members, at different points in time. I understand band A's concern. I would be uncomfortable with members of band A putting effort into other projects which I thought would be better spent on band A. This would be especially concerning in regard to songwriting. However, band B already has songwriters, and I only want to use band B as an opportunity to play more live shows, and expand my musical network. Band B's music is not my favorite style, and it's easy to play, so it seems reasonable to me that my songwriting and musical practice will still primarilly serve to band A.
Fundamentally, I know that band A has no right to dictate how I spend my time. But being in multiple musical groups does set a precedent different than what has been the norm for the past year: that all members of band A are completely dedicated to band A. No matter how it's spun, I can't be completely musically dedicated to band A if I'm also in band B. However I also understand that the average professional musician is rarely a member of a single band. I'm not a professional musician. I have a comfortable day job. But I do dream of someday making some sort of career in music. I'm not talking about being a rockstar, but I mean making some supplemental income, playing some medium-size venues, and having memorable experiences. It seems reasonable that playing in multiple bands is a by-the-book step towards my dream.
I mentioned that my new house with band A has a rehearsal studio and that rehearsal spaces are very hard to come by in my city. Band B rents a space about 30 minutes away from my house, and I have to help pay for the rental space. It would make much more sense for band B to practice at my house. Band B's members are respectful, so I don't worry at all about damage to the house. Practicing at my house is free. And I'm sure band B could establish practice times when the members of band A aren't home.
I asked the members of band A if band B could rehearse at our house at a time when I knew all members of band A we're guaranteed to be gone from the house. Their response was "yes, as long as it is a one-time thing." and "They can't use any of our equipment, and only this once may band B practice at our house." Members of band A said they don't want to share the space/equipment because band B did nothing to contribute to paying for the equipment or house.
Obviously members of band A may say "no one may use MY equipment". However, band A has also purchased a PA system using our gig-income. No one in the band owns this equipment, it's just "the band's". The members of band A don't want the PA system used for band B's practice, but it's very inconvienient to move PA systems. And it seems like a waste of resources to move band B's PA system when there is already one set up at the rehearsal space. Usage of band A's PA system, which is already in the rehearsal room, would not put it at risk. Usage is literally just flipping some switches and plugging in some cables. We'd be playing at levels far below the peak output of the system. Nevertheless, band A's members are not willing to let them use it.
The final issue is use of the rehearsal space itself. The members of band A also don't want band B to rehearse at our house ever again after this one time. This seems very territorial for one thing, it ignores the opportunity to foster goodwill within the musical commuinity. It also would be very helpful for me, a rent-paying tennant of the house. I would save an hour of travel time and save money from not renting an external rehearsal space with band B.
I'm really conflicted. I see how the members of band A might be uncomfortable with band B rehearsing at our house. But I also pay rent at our house. And I think band B could schedule rehearsal times when band A's members aren't even home. If I told my roommates "I want to have friends over to watch a movie while you're out of town", it seems absolutely absurd that my roommates wouldn't be okay with it. But by changing the activity and the location/room of the activity, it falls into a moral gray area.
My specific questions is:
How can I communicate with members of band A to make them comfortable with band B practicing at our rehearsal space, and maybe even use the PA system?