To me it just looks like the type of wording necessary to give them the right to manipulate / stream / embed your stuff when it's uploaded to their site, but...
A2IM: American Association of Independent Music — Blog — Soundcloud Permissions and Scope of its User License
When putting tracks up on Soundcloud, you should strongly consider turning API access off. If you do not do this, you are granting not only Soundcloud a royalty free licence to use your recordings, but also anyone else who uses their API and/or links to your recordings (eg internet radio stations, remix services or other music apps).
Soundcloud’s terms and conditions HERE. The relevant parts are are “Representations and Warranties”, and “Linked Services” under “Grant of Licence”.
A2IM: American Association of Independent Music — Blog — Soundcloud Permissions and Scope of its User License