300 Seamless Loops I Created Made of Orchestra and Drum Elements.   Lengths vary from 3 to 28 seconds each.   Royalty Free Use For All Commercial Projects online and offline.   You can easily edit and convert mp3 files to wav or aif with   a software called audacity for free   https://www.audacityteam.org/   There are free versions for linux, Macintosh and all windows 32 or 64 bit versions. It offers the ability to cut, fade in or out and a collection of cool effects for any audio file!   Older version of audacity can be found here:http://audacitydownloadguide.com/older-versions/