An excellent and relatively unknown Irish band until recently is The Frames. They are a very well renowned and respected band in Ireland but they never hit the same heights as the more commercial acts like Snow Patrol and The Script.
Then, their lead singer (Glen Hansard) won an Oscar last year for the film ‘[W: Once‘ in which he both starred as the lead actor and major contributor to the soundtrack (practically the whole soundtrack to be honest).
Anyways, The Frame’s ‘Seven Day Mile‘ closed the sixth season premiere of NBC’s …

From the Editors Wikipedia:
Editors are a British indie rock band based in Birmingham, who formed in 2002. Previously known as Pilot, The Pride and Snowfield, the band consists of Tom Smith (lead vocals, rhythm guitar, piano), Chris Urbanowicz (lead guitar and synthesizer), Russell Leetch (bass guitar synth and live backing vocals) and Ed Lay (drums, percussion and live backing vocals).
Editors have so far released two platinum studio albums, selling over 2 million copies between them worldwide. Their debut album The Back Room was released in 2005. It contained hits such …

First I’ve heard of this band… so from Mumford & Sons Wikipedia:
Mumford & Sons are a folk band from London. The band is made up of Marcus Mumford (vocals, guitar, drums), Winston Marshall (vocals, banjo, dobro), Ben Lovett (vocals, keyboards, organ), Ted Dwane (vocals, double bass). They formed in late 2007, rising out of London’s folk scene with other artists such as Laura Marling, Johnny Flynn, Jay Jay Pistolet and Noah and the Whale. The band have often supported Laura Marling at concerts, while their association with Noah and the …

From Noah and the Whale’s Wikipedia page:
Noah and the Whale are an Indie folk band from Twickenham, London, England formed in 2006.
The band consists of Charlie Fink (vocals, guitar), Doug Fink (drums), Tom Hobden (fiddle), and Urby Whale (bass), and after a few singles, released their debut album, Peaceful, The World Lays Me Down in August 2008. Laura Marling and Emmy The Great sang for short periods with the band and the brass accompaniment on the CD is provided by Jon Carvell (trombone) and Sam Kinrade (trumpet). Marling still occasionally …

From Coldplay’s Wikipedia page:
Coldplay are an alternative rock band formed in London, England in 1998. The group comprises Chris Martin (lead vocals, keyboards, guitar), Jonny Buckland (lead guitar), Guy Berryman (bass guitar), and Will Champion (drums, backing vocals, other instruments).
Coldplay achieved worldwide fame with the release of their single “Yellow“, followed by their debut album, Parachutes (2000), which was nominated for the Mercury Prize. Its follow-up, A Rush of Blood to the Head (2002), won multiple awards, including NME‘s Album of the Year. Their next release, X&Y (2005), received a …