Back to what Steve was talking about:

I have been busting my ass trying to book shows. I have found that email really sucks for this.
First off it takes them about a week for someone to reply.
Then they may ask for a demo or just download some songs.
Next they might ask which date you need and they will get back to you again, in another week.
In the meanwhile you are dealing with 10 other people like this.
By the guy gets back to you with a confirmation on a date you may have booked that date with somewhere else,
or if he comes back with a no you might have passed on other shows.

Anyway, it sucks. The easiest and best way I have found to book shows is to use the phone. The response is immediate. I get to talk to a voice. There is no bouncing messages back and forth. I can get an answer and move on with my life.

Jeremy wrote:well sound replacing programs didn't exist until late 90s when software recording started really taking affect.

Jeremy

But there were still drum triggers... Nirvana's Nevermind supposedly had the drums replaced.
In the old days it was a MIDI device. You feed audio into it on multiple channels (a channel for each drum) and then you select a replacement instrument on whatever samplers/keyboards you've got.
It is loads of fun to get it all setup and then switch to a non-drum bank or a non-rock kit. The drummer triggers all these seemingly out-of-place instruments and then you start dialing the bank select switch and all hell breaks loose.