A large portion of Zedge. I have a ton of tones I downloaded from them, including just about every carrier that ever had a distinctive ringtone (so my AT&T Note 3 can ring with a 2003 TMobile ringtone or an old Nokia or BB tone). ATM I'm just using an old-fashioned F-style Bell ringer tone. I've used portions of Zarathustra (the "2001 - A Space Odyssey" theme), a Tri-Corder opening, the Star Trek computer "working...". I have special tones for my wife's cellpone, my home phone, my brother, my daughter. Zedge has so many that the problem is choosing one. (I even use AOL's "you have mail" for my email notification.)