callumacrae,
I think you are being either too direct or too broad...
Have you sat down and cleared your mind of everything then said "regarding the topic of music/technology, how can I REALISTICALLY make money?"
Do that...and then it's just a matter of choosing the best idea you came up with and going ahead with it.
I feel what you think I want to create is a forum.
That is not the case, you linked to a number of forums...a membership site is not a forum. A membership site is not a site. A membership site cannot be a forum with special "paid" members-only access sections.
What a membership site does, is create huge dependable income, on a monthly basis, as long as a need is met or a problem is solved.
It's a business. It's offering a service, not a forum. It's offering intellectual information. Information people out there are willing to pay for. That's a membership site. Having a forum helps membership sites. It acts as proof to how many people are in the program, acts as testimonials, acts as a basis to judge and location of niched communication.
You mentioned you know or worked for someone with a forum with a couple million members or posts (not sure which you noted, not looking it up). You also noted it was making $ 200.00 a day from ad space.
That is terrific, it's a story people can look back upon and follow, or mimmick to hopefully make their own profitable forum. If that person converted, half of his members to paying members each at 9.99$ USD a month, he would never need to work again. If he added something in there that converted 1/4 of those members to paying a mere 9.99$ USD a month, he would be set for life as long as he kept his community active and running to it's greatest potential.
He has the user base, has the monthly views but what he lacks is the business model. The membership business model is unique in the fact that once a member joins, and you uphold to the reason they joined you get paid not once, not twice but for years.
That is a true business. A business to which you start, work on, keep active/alive and update every couple of days, hold your part of the deal and get paid for years to come.
Find how to make money with a music site and just do it...you will make it.
Same for a technology site...
BUT...now create/change your idea to fit around a membership model... What will you get? A genius, way to make a living till the day you feel you aren't going to live.