Hi!
I can't speak for any of the other band leaders as far as details go, but I can generalize some of the questions a band leader might ask. I'll try to make it short, I tend to ramble.
Edit: Yeah, that worked out as expected.
Can narrow down the time a bit, to at least a particular day or time of day, like Sunday Afternoon EST? ("Near future" as in next week or July?) Some bands already have set dates/times that they play here and on other servers, and many of us work. Some of us are shiny, happy, morning people, and others are night owls. So you will have to be more specific. Oh, and how long will the party last, roughly? Some might not want to play less than a half hour, some not more than an hour, and many of us would love an excuse to play for several hours, but might not have the time.
In general, you will have a greater chance of having a band of alts play than a band of players, as trying to get multiple players on at the same time is harder than just one player multi-boxing. Also, "small" will mean different things to a band of alts. Some bands could easily just not bring their entire band, just a trio or quartet instead, but other bands only have music ready for their entire band.
Location matters. The farther away from the starter areas and Bree that you go, the less of a chance a band can go there without assistance of some kind. For instance, aside from myself (a champ with no ports), my highest level alt in the band is lvl 36. We pretty much can't just walk into Mordor.
Any particular genre of music you'd like to hear? Most of us can play just about anything for at least a short bit, but all of us have a genre we personally like, and might be more willing to play a set of what we love to play, as opposed to one that we have only 3 songs for.
As far as "hiring"...I'd be surprised if any band leader actually asked for any "payment". Many of us have at some point played to an empty stadium, just to play what we love to hear. I can't speak for the other bands, but I'm pretty sure they would agree, your payment to a band is an "audience". A "tip" on top of that would be to grab some kinnies and go to one of the band's events or cheer them on at Bread & Jam or Elevenses, or show up at one of Xman's parties, or South Bree on many nights.
Those are also great places to advertise about needing a band, asking right when there are multiple bands playing right there.
Of course, bands are weird, so I also wouldn't be surprised if there was a band out there with a 14 page, mind-bogglingly detailed Rider. :p
Grrrrrr. Rambled again...srry. =)