Tonight is the fourth extended play of South Korean boy band Big Bang. It was their first new material released in South Korea after two-year hiatus as a group. Upon its release, the album and its lead single of the same name became a chart-topper in various South Korean and international music charts. It was released on February 23, 2011 under YG Entertainment.
While writing the songs for the then-untitled album, leader G-Dragon and lead rapper T.O.P began to break away to collaborate on their GD & T.O.P project. According to G-Dragon, the group was trying a "new combination" with their music, in which the vocalists Taeyang, Daesung, and Seungri were to record their own music as a trio while the remaining two were to branch off as a duo since they had not been with their fans for the past two years. Although the division of the group was initially for Big Bang's materials only, G-Dragon and T.O.P saw positive response to their materials from the fans and went to Yang Hyunsuk, CEO of YG Entertainment, to allow the duo to release an album. After the promotions for GD & T.OP. collaboration ended, the group reunited to record the tracks to be included for Tonight. Songs from the album have been reportedly recorded variously over the two years span that the group was on hiatus. G-Dragon describes the music from the extended play as "very cheerful" in hopes of cheering up their listeners. Though the group's previous extended plays contained songs that were heavily influenced by electronic music, the group decided to concentrate more on "warm rock music."
"Big Bang’s music has been very cheerful and lyrical so far, but this time we added rock. These days, people seem to find something interesting that can make them laugh and it might come from many accidents and incidents that happened last year, so we are going to present warm and cheerful music for those people rather than heavy and electronic music.” — G-Dragon
After nearly two-year hiatus, Big Bang made their comeback in South Korea in February 2011 which kicked-off with their annual concert, Big Show 2011. There, they also showcased songs from Tonight, performing before an audience of 40,000 fans. The show was aired online by SBS and Mnet. The performance has been hailed as "sensual and stylish" as well as "luxurious" by Lee Soo-yeon of Newsen while it was called "fresh and bold" by Yonhap News, which also went on to state that "Big Bang has come back brilliantly." Park Young-gun of the Star News also applauded the group for their use of lavish props, calling the performance "compelling" and "explosive" and declaring that "Big Bang has come back stronger than ever." The show was watched by a nationwide audience of 5.7%, higher than the 4.9% expected. Revenues from the concert were reported to be ₩43 billion ($38 million).
Teaser photos of the group's music video for their lead single Tonight, which was written solely by G-Dragon with the rap parts written by T.O.P, were also released online. The group also acknowledged their return to the music industry by posting it as their status on Taeyang's Twitter account.Tonight later charted at no. 3 on the Billboard World Albums chart, also no. 3 on the Heatseekers chart, and no. 29 on the Independent Albums chart. It also topped numerous South Korean music chart, including Gaon, Bugs, Soribada, Melon, Cyworld, Dosirak, mobile sites, and Mnet.
The album has received mostly positive praises, with Expo Flat News complimenting it for its "impressive, sophisticated sound textures." The lead single "Tonight" was also praised for its "sophisticated electronic sound" paired with acoustic guitar. Lee Jeon-Hyuk of Sports Chosun hailed the group's comeback as "brilliant" while Choi Jun of Asiae complimented the group's new direction in their music, acknowledging that during the two years of hiatus, the group's "style and musical sensibility [had] deepened." Despite this, the group have been criticized for their over-use of electronic sound. The album has sold 100,000 copies in South Korea.