You need a client_id, but if you don't already have one you might be shit out of luck because 'register a new app' now presents you with a Google Form and the message ***Please allow up to a month to receive an update on the outcome of your application*** ¯\_(ツ)_/¯
gem install httparty
gem install soundcloud
Fill in the client_id and your username, then run it. It will only download tracks that you've already marked as downloadable because who has time to mess with Oauth?