There are more than one artist by this name.
1.) A Swedish dance singer. a.k.a. Petra Marklund
2.) A progressive jazz / rock band from ex-Yugoslavia.
3.) An emo band from the 90's from California.
4.) A Doom/Death Metal band from Sweden
5.) Screamo band from Elkton, Maryland.
6.) A short-lived seventies rock band from Amsterdam, The Netherlands
1.) Petra Linnea Paula Marklund better known as September (born in Stockholm, Sweden on 12 September 1984) is a Swedish dance singer. Her mother is Slovenian and has a musical past and her Swedish father is a professor in space physics. She started recording music in studios at the age of 12. When she was 17, she sang in a rock band and gained a record deal. The songs were written and produced by Jonas von der Burg, Niclas von der Burg and Anoo Bhagavan.
In 2003, at the age of 18, she had her first hit in Sweden with La La La (Never Give It Up), which reached number eight in her homeland. The single was followed by We Can Do It, which became her second top ten hit. As a result of these two singles, her debut album was recorded and released in February 2004, along with the third single from the album, September All Over, which reached the number eight position as well.
It then stayed quiet for September until she broke the silence by releasing Satellites, as the first single from her second album In Orbit, which became her biggest hit to date. The song currently stands at number 139 in the Swedish All-time Bestperforming Singles Chart. Other singles that followed from the same album included Looking For Love, Flowers on the grave, Cry For You (which can now be considered her biggest worldwide hit to date).
In Poland September's second album, In Orbit, was released with new remixes and a DVD with music videos from the album. The album was well received there and peaked at number ten for two weeks, being certified Gold by selling over 10,000 copies.
2.) September (Slovenia, ex-Yugoslavia) was a progressive rock/jazz band active in the 70's. September was founded in 1975 by Tihomir Pop Asanovič and Janez Bončina - Benč. Asanovič had previously played in The Generals, Time, Pro arte and Jugoslovanska pop selekcija and issued two solo EPs, while Bončina was previously the guitarist and singer in Mladi levi, and later the singer in The Generals, Srce and Jugoslovanska pop selekcija, also writing songs.
The band mostly performed jazz rock. They represented the Socialist Federal Republic of Yugoslavia in youth festivals in the USSR, East Germany and Cuba. Vedran Božić, a former guitarist in Time, sometimes performed at their concerts.
In the beginning of 1978, September toured the United States, where they recorded Domovino moja, their second LP, with lyrics by Asanovič and Bončina. The LP included songs that were closer to conventional rock music, with multiple vocal lines. The group disbanded on November 5, 1979 in Zenica, Bosnia and Herzegovina.
In 2003, the album The Best of September was released. The band reunited for a tour with concerts in Pula, Portorož and Maribor, finishing with a performance in Tivoli Hall in Ljubljana, where they were joined by the English group Deep Purple.
On March 30, 2012, the group reunited to perform a concert in Cankar Hall in Ljubljana.
3.) September was an emo band from the 90s. During the entire 8 month span of September's brief presence, the band only managed to play two real shows in their native San Jose, California. Along with the five songs that they recorded, September's demise in May of 1995 left a heartfelt taste of bleak, complex pop that would eventually be pigeonholed into the category of "emo." Not wanting the band to whither away into obscurity, Tree Records released four out of the five songs that would eventually make up the Erasmia Pulcella ten-inch released in 1996. The remanding track can be found on the Love is a Dog From Hell compilation which came out on England's Simba Records.
4.) September was a Doom/Death Metal band from Sweden who had a brief existence during the early 90s. They had one demo entitled "Time of Darkness" released in 1992.
5.) September from Elkton, Maryland. Bandcamp - http://septembermd.bandcamp.com/
6.) September was a short-lived (1970-1972) rock band from Amsterdam, The Netherlands, founded by former members of Anno Nu and De Maskers. Fronted by guitarist, Jan de Hont (of ZZ & De Maskers fame), September released just three singles, including the (very) minor Dutch hit single, 'Little Sister' (1970).