Aiva (http://aiva.ai) generates music up to 3 minutes in the free version (3 phones/month). Advanced editor, unlimited generations, radios, Windows/Mac/Linux app. Tests: https://creators.aiva.ai/publicPlayer?c=652ba0446fda29a03abcaed0 and https://creators.aiva.ai/publicPlayer?c=652c4342bef58b3564dc33a