Public Image Ltd (abbreviated and stylized as PiL) are an English post-punk band (or self-described "company") formed by singer John Lydon, guitarist Keith Levene, bassist Jah Wobble, and drummer Jim Walker in 1978. The group's personnel has changed frequently over the years; Lydon has been the sole constant member. Following his departure from the Sex Pistols in January 1978, Lydon sought a more experimental "anti-rock" project and formed PiL. That year PiL released their debut First Issue (1978), creating an abrasive, bass-heavy sound that drew on dub, noise, progressive rock and disco. PiL's second album Metal Box (1979) pushed their sound further into the avant-garde, and is often regarded as one of the most important albums of the post-punk era. By 1984, both Levene and Wobble had departed and the group was effectively a solo vehicle for Lydon, who moved toward a more accessible sound with the commercially successful albums This Is What You Want... This Is What You Get (1984) and Album (1986). After a late 1990s hiatus, Lydon reformed the group in 2009 and has released several further albums, including What the World Needs Now... (2015).