Audacity is free and pretty easy. If I can figure it out, you can.
Find music YOU like. Look at a video of the horse as you listen to it and see what makes your horse look better (which may not be the exact same beat.) Create a ride To the music, don't cut and paste music to a ride. Have fun.
I have both of the programs mentioned and they are easy to use. Problem I have is removing vocals- both programs claim to do it- but getting the out completely is another story. Many times it doesn't go as hoped. I know it's possible to do as the ppl that made my freestyle last year did it, but I must not have advanced enuf software - the audio formats only have two channels and I havent seen a song with only vocals on the channel- its mixed in like a cake.
It isn't possible to take out vocals unless you own the digital master with all parts on separate tracks. Then you just delete the track. Only the studio which originally recorded the song can take out the vocal. Once all the parts are merged in final mixing, they're in there for good.
Which add ons/plug ins are necessary for the audacity or is just the beta version a good place to start?
I teach Audacity to undergraduate college students quite often, so I can answer this. The Beta is fine to start. You don't really need plugins. If you plan to export your final file in MP3 format, you'll need the LAME Encoder. The Audacity web site has excellent instructions for installing that.
Audacity's been around for a long time. I do strongly suggest you check out some Youtube tutorials for it; it's easier to learn that program by example. This is one that I made last year for students, and I've queued it up to the 4-minute mark (which is where I actually start talking about the program and showing the main controls): http://youtu.be/wyAEGBr1OnI#t=04m00s