continued from this page Loops (Continued) - When you add an Apple Loop to the timeline, it is matched to the key of the song. If you change the key of the song, the regions created from the loops are transposed to the new key. GarageBand can also use loops created for other music software. In some cases, these loops may not be matched to the key of the song, or may not be transposed if you change the song's key. (In which case it can be done manually) - You can add a loop or other audio file (in AIFF, WAV, or MP3 format) to a song by dragging it directly from the Finder to the timeline. You can drag the audio file either to a Real Instrument track or to an empty area below the existing tracks. When you add an MP3 file by dragging it to the timeline, the file is converted to an AIFF file which is stored as part of the song. Recording - To play the onscreen keyboard, click the notes on the keyboard. You can click when the song is playing or stopped, and record by clicking during recording. Clicking notes lower on the keys plays notes with higher velocity, and clicking higher plays notes with lower velocity. - You can also connect a MIDI-compatible music keyboard to your computer to play and record Software Instruments. - You can connect a microphone to your computer using the computer's audio in port, if your computer has one. You can also connect an audio interface to your computer, then connect instruments and microphones to the audio interface for recording. Audio interfaces are available in a variety of compatible formats, including USB, FireWire, PCI, and PC card formats. You can also connect an audio mixer or console to your computer, and record microphones or instruments through the mixer. - When you add a Real Instrument track, you select the input channel (or pair of channels, for stereo input) for the instrument in the New Track dialog. You can change the input channel, and whether the track uses mono or stereo input, in the Track Info window. You can also turn on monitoring so you can hear the instrument before recording. (According to one report, you can record two mono channels simultaneously) Editing - You can edit individual notes in a Software Instrument region to adjust their timing, length, and pitch. You can also copy, paste, and delete notes. The notes in the region are shown in a graphic "piano roll" format. The left edge of a note shows where it starts in the timeline. The length of a note shows how long it plays. The vertical position of the note shows its pitch in relation to the piano keyboard displayed along the left edge of the editor. Each note also shows how hard you pressed the key when you played the note (called the note's "velocity"). Notes played softly are lighter gray, and notes played more intensely are darker. Many Software Instruments change their sound depending on how hard you press the key. - Files are exported to iTunes in AIFF format. You can convert the exported file to another format, such as AAC or MP3, from within iTunes. Performance - The maximum number of notes Software Instruments can play at once depends on the CPU of your computer. - The maximum number of Real Instrument tracks and Software Instrument Tracks your songs can have depends on the amount of RAM memory installed in your computer.