Create a piece of music that will be your ring tone (minimum of 10 seconds - we will loop it)
Record your ring tone - use Bandlab (on your chromebook) or Audcity (on the classroom desktop computers)
Export your finished recording as an MP3 file
Share your file to a phone (bluetooth/email/cloud share)
In the phone settings - choose notifications - ring tone - select the mp3 file you created
Now call the phone and listen to your masterpiece