There are at least 2 bands with this name: 1) T9 - folk-rock from China
2) T9 - hip-hop from Russia --- T9, sometimes T-9 was a rock band from Beijing, that combined rock music with traditional Mongolian music. Yiliqi, son of a Mongolian and a Mandshurian, formed his first band in 1996 and at that time he did nothing close to Mongolian folk music. The name was Qingpi, which translates as lazy person, and can be categorized into the grunge genre. Even as he formed T9 in 1998, he was mostly interested in music from bands such as Rage against the machine' and other hardcore bands.

Read more about T9 on Last.fm.