NEED help for sentences meaning

Hello, My felows. Below is a weblog by music fans. Would you please tell me the meaning of these sentences?I'm not sure about it. Thank you!
Thanks for the list, Funk! Wrote 'em down and will be looking into some of them when the money ain't funny.

And judging by the "large" response to the thread, you were on the money when you mentioned the being "hung-up" on old hat guitar heros!

[Tdol]

1 The money ain't funny- I'm guessing here, but I imagine it means when they have more time; they are very busy working because they are short of money.

2 (bang) on the money = correct

3 Hung up = very interested in, usually in a negative way. In other wordss, they are really into old fashioned guitar players, which the sriter probably isn't.

I have never seen the word ain't. What does this mean?

Do I have any mistakes in my language us above?

[Tdol]

'Ain't is a colloquial general purpose negative. It can be 'isn't, 'aren't,'don't', 'haven't', etc. It's not used in formal language and is more common in spoken.