Editing an MP3 song using GarageBand is quite simple thanks to GarageBand’s user-friendly interface. Once you’ve imported the MP3 to GarageBand, the song can be manipulated using a variety of built-in effects, editing and mixing tools. For Macintosh users, GarageBand is free and comes factory-installed on all Macintosh computers.
Create a new GarageBand session by clicking “File” and selecting “New.” Then click “New Music Project.”
Give the new GarageBand session a name, such as “MP3 Edit,” and then click “Create.” This will open a new GarageBand session.
Drag the MP3 song into the edit window to import it into GarageBand.
Edit the beginning or end of the MP3 song by hovering your mouse over one of the ends until an arrow appears. Once this arrow appears, click and drag the end of the MP3 file to cut off audio content from the beginning or end of the song. If you cut off too much content, simply drag the arrow the other way to expand it.
Create a volume fade by clicking the downward-pointing arrow underneath the MP3's track name. Doing so will open a "Track Volume" line underneath the MP3. Click this line to create a break point and then drag that break point up or down to create a volume increase or decrease in the MP3 song. You can create as many break points as you would like in order to manipulate the volume of the MP3 song.
Click the “View/Hide the Track Info” button on the bottom right-hand side of the program. Then click the arrow next to “Details” to add effects to the MP3 song. Within this menu you can add compression, equalisation, reverb, distortion and a variety of other effects to the MP3 song.
Export the MP3 song from GarageBand when finished editing it. This can be done by clicking “Share” and selecting “Export Song to Disk.” Then give the file that you are exporting a name and click “Save.” You have now successfully edited an MP3 song using GarageBand.