There are at least nine "Contra's", they will all be dealt with below. 1. Contra was a hardcore/punk band from Long Island, New York. They formed around 1997/98 and at the time were Jon Berg, Steve Andolfo, Anthony Greco, and Craig Hughes. They toured a few times, released a couple of records on Traffic Violation records, and defined what hardcore and punk was about for a lot of people on Long Island for a long time.
There are at least three bands called Ohm, one from Stockholm, Sweden and another from South Africa and lastly Chris Poland's Ohm: from L.A california. Ohm: is a Chris Poland (a former member of Megadeth who has also worked with Lamb Of God) experimental jazz fusion project formed by Robertino Pagliari and himself. The band was formed in 2002 and has released 3 LPs and a live album up to date. It should be noted however, that ohm is incorrectly tagged on last.fm... the true title of Ohm: includes a colon, according to Chris Poland this is due to their constantly changing drummers.