Need help to identify an instrument

Question

Can someone please help me identify a bass instrument found in the following video?

It plays through out the song, but at 2:15 - 2:25 and 2:55 - 3:05 you can clearly hear it play. It is the deepest sound at that part. I don’t think it is a double bass. If it is not a double bass, then I really don’t know what to make of it. The sound is gorgeous.

Answer 1

Bass guitar. Possibly fretless. Listen to the characteristic gliss down into the section just before 2'15".

Answer 2

It sounds pretty much like a fretless electric bass.