How to change a Pitch of a song in Garageband 11?

Now i want to change a pitch(tonality) of a song?

What kind of song? Is it an audio file or a GarageBand project?

GarageBand 10 does no longer support transposing audio files.

You can convert your audio file to a loop or use the AuPitch filter.

• To add the audio file to the Loop Library trim it to an exact number of measures. Then select it and use the command "Edit > Add to loop library".
• Make sure the type "Loop" is selected and not one-shot.
• Click "Create". Now you can delete the original region and add the loop from the Loop Browser. And now the Transpose slider should work.

To transpose using the AuPitch filter:

• In the new GarageBand you add the AuPitch filter from the Smart Controls.
• Enlarge the SmartControl panel by dragging the dividing line upwards, until you see the Audio Units brick, then add an Apple Audio Unit and set it to AuPitch.

The methode I described will change the pitch.

When you convert your audio file to a loop, it will change the pitch, when you add it as a lop to the project and then change the key of the project in the LED display.

If you prefer the AuPitch filter:

• In the new GarageBand you add the AuPitch filter from the Smart Controls.
  Enlarge the SmartControl panel by dragging the dividing line upwards, until you see the Audio Units brick, then add an Apple Audio Unit and set it to AuPitch.
• 

But know i don't know how to save the repaired song in mp3 format.What about the quality? Is it the same?Or when i shift the pitch it goes worse?

How much do you want to shift the pitch? A few half tone steps will be o.k. with AuPitch filter, but if you shift over a larger range it may sound funny, particularly, if vocals are involved. Then you would be better off with a vocal transformer, so you can correct the formants as well.

To export as a mp3 use the "Share" menu: Share > Song to disk.

Then use these settings:

I will try it now! I must shift the pitch(decrease) with half or whole tone or more..

A half tone or while tone will be no problem with the AuPitch filter.

Decrease or increase the pitch - the wheel steps the pitch in cents - 100ct are a half note.

GarageBand 10 has only the Vocal transformer, if you have also GarageBand '11 installed. Then you can also adjust the formanats.

But GarageBand '10 has at least a pitch shifter in the for the vocals in the Voice > Experimental > Deeper Vocals patch:

If you have GarageBand '11 still installed, you should also see:

Legacy > GarageBand > Voice > Deeper Vocals, which has a Vocal Transformer and lets you adjust the formants.

I am not sure if here i don't make a mistake,when i choose Empty project, with "Tempo" or "Key Signature".

That should not matter, since it is an audio file.

Try, if using the second mehod - adding the audio file to the loop browser, will give better results.

Estimate the key and the tempo of your song, and create an empty project with these setting.

• Add the audio file to a track.
• To add the audio file to the Loop Library trim it to an exact number of measures. Then select it and use the command "Edit > Add to loop library".
• Make sure the type "Loop" is selected and not one-shot.
• Click "Create". Now you can delete the original region and add the loop from the Loop Browser.
• Use the Transpose slider to transpose the loop of your audio file.

To estimate the tempo start a stop watch and try to clap at each beat - count the beats per minute.

To find the key of the song you'll have to listen to it. Do you have sheet music of the song? Then try to play it and compare to your audio file.