Averaging at about 65 BPM, the genre that is also referred to as 'Sadcore' is as slow as it can possibly get for listenable music. This small yet quite defined genre slowly evolved during the 90s, especially in the USA. It sounds like quiet indie pop, only much slower. Very melodic, very atmospheric, and very, very, sleepy.
Not very danceble, Slowcore music usually sounds better while lying under your favourite blanket (or person) in a cold and rainy winter day, with a hot cup of your favourite hot drink in your hand.
Key bands :
Recommended listening (some good examples of good slowcore, IMHO) :
This is one nodeshell I enjoyed rescuing.