U2 are an Irish rock band from Dublin, with Bono as the lead singer and rhythm guitarist; The Edge on lead guitar, keyboards, and backing vocal; Adam Clayton on bass guitar; and Larry Mullen Jr. on drums and percussion. The band chose the name "U2" for its ambiguity and open-ended interpretations, since the letter "U" is pronounced just like the word "you," and "2" can be interpreted as "two" or "too." Since their formation, U2 have developed and maintained a distinctly recognizable sound, with emphasis on melodic instrumentals and expressive, larger-than-life vocals. They are also known for their involvement in political and social causes.