Answer by taking a quote from the following article:

Adrian Frederick "H" Smith (born 27 February 1957) is an English guitarist, best known as a member of Iron Maiden, for whom he writes songs and performs live backing vocals on some tracks. Smith grew up in Camden, London and became interested in rock music at 15. He soon formed a friendship with future Iron Maiden guitarist Dave Murray, who inspired him to take up the guitar. After leaving school at 16, he formed a band called Urchin, which he led until their demise in 1980.

In 1999, Smith re-joined Iron Maiden, along with vocalist Bruce Dickinson, who commented, "When he left the band in 1990, I think everybody was a bit surprised at how much we missed him and certainly, I don't think anybody had realized how much the fans would miss him - big time. I wouldn't have rejoined Iron Maiden if he wasn't in the band. I just don't think it would have been complete without Adrian, and now, it's great having three guitarists." The band embarked on a short tour, after which the new line-up's first album, Brave New World, was recorded with producer Kevin Shirley and released in 2000. He remains in Iron Maiden, with whom he has released four further studio albums, 2003's Dance of Death, 2006's A Matter of Life and Death, 2010's The Final Frontier and 2015's The Book of Souls. Smith claims that his guitar playing improved after leaving the band in 1990, in particular while working with Roy Z, from whom he "learned a lot about picking" and became "more disciplined." Since returning to Iron Maiden, he has also continued experimenting with tuning (which he began doing in Psycho Motel), stating that he has used drop D tuning in live renditions of "Run to the Hills", "Wrathchild", "The Trooper" and "Hallowed Be Thy Name". Although Smith had previously been known to contribute shorter, more "commercial" tracks, since his return to the band he has penned many longer songs, beginning with "Paschendale" from Dance of Death. Smith performs lead guitar, bass and backing vocals on the album Awoken Broken by his collaborative studio project with Mikee Goodman of SikTh called Primal Rock Rebellion. The title was released on 27 February 2012, while one song, "I See Lights", was released as a free download on the project's official website on 2 January.

What were some notable singles off the albums?
"Run to the Hills", "Wrathchild", "The Trooper" and "Hallowed Be Thy Name".