Recently I had a few minutes to try out GarageBand in conjunction with the
Symphony Orchestra Jam Pack (just 100 USD).
To me this software is astonishing powerful and -what's more important- easy to use.
I can recommend this product to any beginners, but also as an uncomplicated sketch-book for professionals.I use it to draft my quick ideas on my iMac, when I'm to lazy to boot my complete studio.
Here is a short example, a remix of 'The Endless Enigma' an old title of mine:
I use Garage Band in an educational setting, and after about three days, no matter which kid sat down and used the program (very talented with lots of background, to the rank beginner) all of the songs would sound the same.
It is definitely composing by numbers...1..2..3.. it as easy to learn as your A..B..C..D..E's.