copyright

I have created an arrangement of Somewhere Over The Rainbow by Harold Arlen. I would like to post it on MuseScore. I have read that Hal Leonard Corporation own the copyright. I tried to find contact information, but got into a loop that did not lead to a simple email contact. Must I contact them first or just upload the arrangement since I will be taking no credit for composing the original song? I ask because I was prevented from having What'd I Say by Ray Charles on the MuseScore site because of copyright infringement.