What: Jon the dog = Solo organ and vocals
Link: Jon the dog webpage (Japanese)
The most noticeable aspect of a Jon the dog performance is that the performer is dressed in a giant (and scary) dog costume. This shouldn't be taken to mean that the project is a gimmick; Jon's music is compelling by itself. But the dog suit definitely adds something important - a surrealness that helps the music along.
Enban boss Taguchi-san once told me that all of Jon the dog's songs are about the life of a dog. However, "男の世界" (Otoko no sekai = "A man's world") could just as well be about sexual politics, at least according to my limited understanding of the lyrics.
Aside from the music, Ms. Jon leads an interesting life as a fortune teller and a proprietor of a bar in Golden Gai (unfortunately she doesn't wear the dog suit when serving drinks).