I bought a WK 1800 at the Guitar Center in Hollywood, (on sale for $399 which is a great price)... I can't find where I can buy the "Music Pattern Disks" they talk about... any clue where they are sold? Also, they show some CD roms also, what are they? I normally play an Alesis QS8.1, but it's too heavy to move around... this Casio is VERY lightweight, and the 76 keys make it much better than anything with only 61 keys in my mind... the sound out of the built in speakers is INCREDIBLE for this price...thanks, jim