OK then, with a few additions too:

As a promoter, I would recommend other promoters treat putting on gigs as taxable income. Even if it's not your main source of income (even if it's not a source of income at all – perhaps even especially so in this instance). Room hire charges and performer's fees are claimable expenses. Do it properly, and fill out a tax return every year. If you have to fill out a tax return already (eg for any kind of freelance work) and you promote gigs, then doubly so. And if you are a musician as well as a promoter, then even more so (as the amount of claimable expenses can include musical instruments, travel etc).

I often think it's a shame that private companies/investors don't put on concerts as a tax loss. It'd be brilliant for the live music scene.