he's my favorite singer; im glad people recognize him. especially in MBTI forums.
to my surprise, this is exactly the types im thinking he might be.
he can be an ISFP. because, not only he's artistically quirky (the male lady gaga as i call him), but he's also expressive artistically. INFP singers wont care much about artistic expression. they will care about the "idea" in their song, which is why their music "all sounds kinda the same" (examples: owl city) (this is not a bad thing. it just means that ISFPs and INFPs fills each others weaknesses)
but, on the other hand, he can be an INFP because the ideas behind his songs are also a strong point XD the topics he chooses for his songs, and his songs' layout... he kinda acts like an INFP (and im talking about mechanism. not the "N people are deep" stereotype)
which leads us to a third possibility that he's an INTP. "he...kinda seems like a T to me" - my INTP sister when i made her listen to him. unlike I FP's, INTP's are naturally workaholics, and theyre not easily distracted. this is why, even though their ideas are a strong point (because theyre N), their artistic skills are also extremely evolved. (my sister is an INTP, and she's VERY accomplished in manga. artistically and in ideas. an example, if you will)
to be honest, im not sure which type he is.