The MP3 file was created using a program called Audacity 2.1.0, which was a free download. It was a full version and worked great. I tried other programs, but this one was the best. I used my own recording 4 times and also used three excellent songs. Two songs were from the band Chicago and one from the band Earth, Wind and Fire. I exported the songs to an MP3 file. My file size was 3.74 MB with a length of 4 minutes.