There are at least 4 bands with this name.
(1.) Howl is a sludge metal band from Providence, RI (http://www.myspace.com/howlheavymetal
(2.) Howl is a Norwegian alternative rock band from Oslo (http://www.myspace.com/howl1)
(3.) Howl is an Indie Punk band from Ballarat, Victoria, Australia. They rose to prominence within the Melbourne Indie music scene after winning Triple J's Unearthed High 2009. (http://www.myspace.com/thehowlmusic)
(4.) HowL is a korean pop singer.