Need some help with recording backup instruments

[regulator1]

Hi Guys,

I guess this is the best place to post this..

I have just started playing out again with a few friends after a 20 year vacation..

I have an opportunity to get a gig at a local establishment a few weekends a month..

Here is my dilemma

The drummer in the band can't commit to playing out more than one night a month.. So..

I want to buy/or somehow record the backing Drums, Keyboard and bass onto my Ipod or Ipad and plug that into my pa..

Then trigger the song so I can Play guitar and sing either by myself or with another singer/guitar player...

I used to do this 20 years ago but, those cassette tapes (Some of you might remember these) are long gone..

I am a little computer savvy, but I am not a drummer or keyboard player...

Is there a place to buy certain songs in this format?

Any help is very appreciated...

Thanks

Jeff