GarageBand is a music application by Apple that can be download in the Mac App Store and iOS App Store. In it, there are some virtual instruments for you to play and practice. Take the drums for example; you can get three acoustic drum kits including snare, toms, kick, cymbal and hi-hat. And the harder you hit the drum, the stronger the tone.
To help you to use the GarageBand, this article lists some Get-Started hints. GarageBand for iPad for example:
1. Add effects to a Guitar track
Open the track info pane, and tap on the guitar amp, then tap the Edit button on the top corner of the screen to spin the amp around. Then go to the back of the guitar amp, click the arrow pointing upward in the lower pane, then you can see a single effects slot where you can choose from the standard effects provided.
2. Rename a region within a track
Open the track editor in the GarageBand for iPad, then you will see the current name of the track at the left top corner of the region, double tap the track name and type the new name what you prefer.
3. Add your own templates to GarageBand (Mac version for example)
There is an app enables you to do so as simple as drag & drop. It names My Template Installer. First of all, you need to add your own templates into the new project startup menu in the new iPad GarageBand. And there is a quick start: if you like to start a GarageBand project to record and tracks of drums, you are suggested to set up a project as a template, then create an image and display it in the windows of GarageBand’s new project, save it as a TIFF file. Now add the file into Drop Zones and enter the template name. tap the Install button.
4. Import an audio file
To import audios into the GarageBand, you have to make sure of two things: the audio format has to be compatible with Apple products no matter if you are using a Mac or a new iPad. That’s to say, if you have a WMA audio file, you need convert WMA to iPad audio format (MP3, AAC, FLAC etc.) first. Also you need make sure the audio file is DRM-free. If you purchased the file via Ovi center, Zune media store etc., the audio files are likely DRM protected. If so, you'll need to remove the DRM protection first. So if you have guaranteed your files are in a compatible format and are without DRM protection, then you can drag & drop the file into a blank area of the timeline or a “Real” track.
More instructions: GarageBand for iPad Manual