Initially rooted in post-punk, U2's musical style has evolved throughout their career, yet has maintained an anthemic quality built on Bono's expressive vocals and the Edge's chiming, effects-based guitar sounds.

[10] In March 1978, the group changed their name to "U2",[12] selecting it from a list of six options suggested by Steve Averill, a punk rock musician with the Radiators from Space and a family friend of Clayton.

[18] Irish magazine Hot Press was influential in shaping U2's future; in addition to being one of their earliest allies, the publication's journalist Bill Graham introduced the band to Paul McGuinness, who agreed to be their manager in mid-1978.

[34] Paul Morley of NME called it "touching, precocious, full of archaic and modernist conviction",[35] while Declan Lynch of Hot Press said he found it "almost impossible to react negatively to U2's music".

On an American leg of the Boy Tour, Bono's briefcase containing in-progress lyrics and musical ideas was lost backstage during a March 1981 performance at a nightclub in Portland, Oregon.

[43][44] The band had limited time to write new music on tour and in July began a two-month recording session at Windmill Lane Studios largely unprepared,[45] forcing Bono to quickly improvise lyrics.

[45] Adding to this period of self-doubt, Bono's, the Edge's, and Mullen's involvement in a Charismatic Christian group in Dublin called the "Shalom Fellowship" led them to question the relationship between their religious faith and the lifestyle of a rock band.

The decision to hire them was against the wishes of Island Records founder Chris Blackwell, who believed that just when the band were about to achieve the highest levels of success, Eno would "bury them under a layer of avant-garde nonsense".

[98] The wild beauty, cultural richness, spiritual vacancy and ferocious violence of America are explored to compelling effect in virtually every aspect of The Joshua Tree—in the title and the cover art, the blues and country borrowings evident in the music ...

[108] The record went to number one in over 20 countries,[109] including the UK where it received a platinum certification in 48 hours and sold 235,000 copies in its first week, making it the fastest seller in British chart history at the time.

[162] Mullen was sidelined due to back surgery in November,[163] prompting the other band members to take different approaches to songwriting, such as programming drum loops and playing to samples provided by Howie B.

[195][199] For many of those not won over by the band's forays into dance music, it was considered a return to grace;[200][201] Rolling Stone called it U2's "third masterpiece" alongside The Joshua Tree and Achtung Baby.

[214][215] Following the September 11 attacks in the US, All That You Can't Leave Behind found added resonance with American audiences,[216] as the album climbed in the charts and songs such as "Walk On" and "Peace on Earth" received radio airplay.

[288] In February 2014, the single "Invisible", debuted in a Super Bowl television advertisement and was made available in the iTunes Store at no cost to launch a partnership with Product Red and Bank of America to fight AIDS.

[311] The group had mostly completed the album and planned to release it that year, but after the shift of global politics in a conservative direction, highlighted by the UK's Brexit referendum and the 2016 US presidential election, they put the record on hold to reassess its tone.

[330] The band incorporated augmented reality into the shows, releasing a mobile app for concertgoers to use and reviving Bono's demonic stage character MacPhisto from the 1993 Zoo TV Tour with the help of a camera filter.

Performances were focused on the group's 1991 album Achtung Baby and leveraged the venue's immersive video and sound capabilities, which include a 16K resolution wraparound LED screen and speakers with beamforming and wave field synthesis technologies.

Mullen did not participate in the concerts in order to recuperate from surgery,[353] marking the first time since 1978 that U2 performed without him;[354] Dutch drummer Bram van den Berg from the band Krezip filled in.

[226] Their songs began as minimalistic and uncomplicated instrumentals heard on Boy and October, before evolving with War to include aspects of rock anthem, funk, and dance rhythms to become more versatile and aggressive.

[81] The songs from The Joshua Tree and Rattle and Hum placed more emphasis on Lanois-inspired rhythm as they mixed distinct and varied styles of gospel and blues music, which stemmed from the band's fascination with America.

[369] According to Stephen Thomas Erlewine, "U2 was able to sustain their popularity in the '90s by reinventing themselves as a post-modern, self-consciously ironic dance-inflected pop-rock act, owing equally to the experimentalism of late '70s Bowie and '90s electronic dance and techno".

[372] The band's 1990s output has been regarded as an art rock phase in commentaries by biographer John Jobling,[373] Salon journalist Nico Lang,[374] and music critic Jim DeRogatis,[375] as well as in an interview by Bono.

[376] Time magazine's Josh Tyrangiel went further in saying that, "In the towering period that spanned The Joshua Tree to Zooropa, U2 made stadium-size art rock with huge melodies that allowed Bono to throw his arms around the world while bending its ear about social justice.

"[382] Summing up U2's stylistic evolution since Boy, Guitar journalist Owen Bailey said that they "have gone on to conquer the world's airwaves and arenas in a number of different incarnations, ranging from earnest, politically charged new-wave flagbearers to wide-eyed art-rock musicologists to purveyors of irony-laden alt-rock and ever onward", with the Edge remaining "at the heart of their sound".

[395] Bono's vocal style evolved during the band's exploration of roots music for The Joshua Tree; Spin said that he learned to command "the full whisper-to-shout range of blues mannerisms".

[405] His singing on Zooropa was an even further departure from U2's previous style; throughout the record, Bono "underplay[ed] his lung power", according to Jon Pareles,[406] and he also used an operatic falsetto he calls the "Fat Lady" voice on the tracks "Lemon" and "Numb".

[417][418] Among the Edge's signature techniques are playing arpeggios,[31][417] sixteenth note percussive strumming,[419] and harmonics,[414] the latter of which he described as "so pure and finely-focused that [they have] the incredible ability to pierce through [their] environment of sound, just like lightning".

[444] In the band's early years, Clayton had no formal musical training,[445] and he generally played simple bass parts in 44 time consisting of steady eighth notes emphasising the roots of chords.

[369] While the band and its fans often affirm the political nature of their songs, U2's lyrics and music were criticised as apolitical by Slate in 2002 for their perceived vagueness and "fuzzy imagery", and a lack of any specific references to people.

[518] Record sales declined in the 2000s and the music industry entered an age of often illegal digital downloading, but according to author Mat Snow, U2 prospered more than younger acts because of a loyal following that held an attachment to the album format.