There are several artists named Decay:
1) Decay is a Black/Death/Doom Metal band from Oradea, Romania
2) A goregrind band from Finland.
3)A heavy metal band from Greece.
4) A hardcore punk band from Japan.
Miki Inohara/Jun-ichi Takahashi/Nobuhide Takahashi/Kiyohiko Aoki
5) A Death Metal band from Luxemburg.
6) Hip Hop artist from CHICAGO, Illinois, United States
7) A Thrash/Death Metal band from Dayton, Ohio
8) An Electro-Rock Band From Bordeaux, France, who play a mix of NIN-like metal with hip-hop beats.
9) Black Metal from Parede, Lisbon, Portugal, Formed in 1990
10) A gothic rock band along the lines of Gene Loves Jezebel from Hamburg/Germany. They released two CDs, Winterfields (1994) and Downstairs Rise (1997), and then split up. Today guitarist lib.Ed. is going solo, while bass player Michelle now plays with Dark Orange.
11) An Electro artist from the UK (http://www.myspace.com/decaynet)
12) Decay is a doom/death metal band from Cezch Republic
13) A Death Metal band from San Diego, USA (split-up)