The 2011 iMac comes preloaded with the iLife software bundle, which includes GarageBand.
The 2011 iMac does not come with a 3.0 USB port. It has four 2.0 USB ports. The new 2012 iMac does have four 3.0 ports.
iLife is a suite of applications, found in the Applications folder, which includes iPhoto, iMovie, Garageband etc.
The G3 iMacs were discontinued in 2003 and Garageband was not launched until 2004 so they would not normally have had Garageband installed. If an early version has been installed on a G3 iMac it will be of limited use as Garageband requires considerable processor power to handle multi-track compositions for which the G3 processor would not be suited.
Lion is due for general release in July 2011.
Apple no longer sells a 20" iMac. They sell a 21.5" and 27" iMac. Both come in aluminum.
iMac's do not come with night vision.
The iMac was invented and went on sale in 1998. The iMac as it looks today was introduced in 2006.
You can use the midi output from the EZ 200 to control Garageband. You will need an adapter to connect the midi lead to the Mac's USB socket. (See links below)
1998
The original iMac was the G3 which came out in (1998). It was followed by the G4 (2002), then the G5 (2004), then the Intel iMac plastic version (2006). The 5th iMac was the aluminum iMac which came out in (August 2007), followed by the iMac Aluminum Unibody (2009). The newest iMac is simply called 2012 iMac and it came out on November 30, 2012.
You have to purchase Photoshop separately.
A G4 iMac needs to be running at 867MHz or faster with Mac OS X v10.5.6 Leopard to use most of iLife '09.Neither iMovie nor GarageBand's Learn to Play feature will work as they require an Intel-based Mac with a dual-core processor.