GarageBand
GarageBand is an app for creating, recording, and sharing your music. It has everything you need to learn to play an instrument, write music, or record a song—your own home recording studio.
Create a new project. You can start with a song template, select a tempo, key, and other options, then click Record and start playing. Build your song—for example, with different tracks and loops. Click Quick Help 
and hold the pointer over items to learn what they are and how they work.
Bring in the beat. You can quickly add drums to your project using Drummer Loops. Click the Loop Browser 
, then drag a Drummer Loop 
into an empty part of the Tracks area. You can customize Drummer Loops to fit your song, using a simple set of controls.
Record your voice. Connect a microphone, choose Track > New Track, then select the microphone under Audio. Click the triangle next to Details to set options for input, output, and monitoring, then click Create. Click the Record button 
to start recording, or click the Play button 
to stop recording. (Accessories are sold separately at apple.com, your local Apple Store, or other resellers.)
Learn more. See the GarageBand User Guide and GarageBand Support.