MP3s are almost universally accepted when a digital function calls for a compressed sound file. You can use iTunes to convert other file formats (e.g., AAC and WMA) to MP3.
1. Open iTunes and go to Preferences (in Windows select Edit, then Preferences; in Mac choose iTunes, then Preferences). On the General tab, click Import Settings. Under the Import Using pop-up menu, select MP3 Encoder, then click OK.
2. If the music file isn't already in your iTunes library, click File on the menu bar, then select Add File to Library. Locate the file on your computer, then click Open to import the file into iTunes.
3. Select the file to be converted, then click Advanced on the menu bar. Choose Create MP3 Version. ITunes will create a duplicate in MP3 format. If you need the MP3 for another project, click on and drag it outside of iTunes to create a copy of the file.