Cacophony

You begin a chorus of unruly music featuring dangerously loud noise levels. All creatures that can hear you within 300 ft. of you take 6d6 thunder damage at the end of each of your turns for the duration. Also for the duration of this spell, any creature that starts its turn with within 60 ft. of you must make a strength saving throw or be pushed back 20 ft. 

 The noise this spell creates can be heard from up to 1 mile away.