There have been a number of artists going by the name of Siddhartha:
(1) A screamo band from Memphis, TN
(2) A band formed in Istanbul Turkey in 1990s and disbanded in 2001
(3) A German progressive rock band of the 70s
(4) A singer-songwriter from Mexico
(5) A young Polish reggae band from Wrocław Siddhartha (1)
Siddhartha was a screamo band from Memphis, TN that existed from December 2011 to June 2013. In June 2012, they digitally released a four song EP entitled "Subject to Change." Before disbanding in June 2013, they recorded a six song EP entitled "Denouement.

Read more about Siddhartha on Last.fm.