Task: Question Answering
Input (English): Passage: Steven Lee Lukather (born October 21, 1957) is an American guitarist, singer, songwriter, arranger and record producer, best known as a founding member of Toto. A prolific session musician, Lukather has recorded guitar tracks for more than 1,500 albums representing a broad array of artists and genres. He has also contributed to albums and hit singles as a songwriter, arranger and producer. Lukather was a prominent contributor to several studio albums by Michael Jackson, including Thriller, the best-selling album of all time. Lukather has released seven solo albums, the latest of which, Transition, was released in January 2013.
In 1976, when Lukather was nineteen years old, he was invited by his high school friends David Paich and the Porcaro brothers Steve and Jeff to join them in forming their band, Toto. He has been a member of the band ever since it began, and is still fully contributing to their album composition and touring. Lukather's reputation as a guitarist and his association with Paich and the Porcaro brothers, who also became established artists, allowed him to secure a steady flow of session work in the 1970s and 1980s. Lukather has been nominated for twelve Grammy Awards, and has won five. While his work with Toto was predominantly based on pop rock music and his solo work ventures into progressive rock and hard rock, many of Lukather's side-projects are focused on jazz fusion. He held a long-time collaboration with jazz guitarist Larry Carlton that produced a Grammy-winning live album, and he was a member of the jazz fusion band Los Lobotomys, a collaboration of notable session musicians. Since 2012, Lukather has toured with former Beatles drummer Ringo Starr's live supergroup, the All-Starr Band.
Influenced by such blues-rock guitarists as Jimi Hendrix and Jimmy Page, and such jazz fusion players as Al Di Meola and Frank Gambale, Lukather is known for a "melodic and intense" playing style. He is also recognized for his efficiency in the studio, often recording tracks in one take using minimal sound processing. While he once used many guitar effects in the studio and on stage, he now frequently disparages such practice, and instead advocates clean tones and minimal studio processing. Lukather plays primarily a signature electric guitar manufactured by Ernie Ball Music Man bearing his nickname, Luke. He also plays Yamaha and Ovation Adamas series acoustic–electric guitars. 
Question: What is the last name of the person who was invited by his high school friends to form a band?
Output (English): Lukather.