Question: Which guest musician from the American hard rock band formed on Long Island, New York in 1969 appeared on Step Back?
Context: Live...The Best is the first live album by the hard rock band Bonfire.  It was released in 1993 on the label RCA Records.  It is a live concert recording done in Germany from the Point Blank Tour in 1989 and 1990.  Michael Voss was a guest musician, as well as Andreas Knote, for the on stage performances.  It is the last album before the band's break-up in 1994 and reunion in 1996.  When this was released, Claus Lessmann had already left the band and replaced with Michael Bormann. Paul Nelson is a Grammy-winning American guitarist, performer, record producer, and songwriter.  Who has worked with everyone from Eric Clapton to members of the Allman Brothers Band and the list goes on.  He was in the blues rock band of guitarist/singer icon Johnny Winter.  He produced and played on several of Winter's albums, including the Grammy-nominated "I'm a Blues Man", "Roots", "Step Back".  The latter of these won him a Grammy Award for Best Blues Album, debuted at #1 on the "Billboard" chart for Blues Albums and Independent Albums, and debuted at #16 on the "Billboard" 200 albums chart, the highest spot in Winter's career.  It also won the Blues Music Award for Best Rock Blues Album.  Nelson was inducted into the New York Blues Hall of Fame and is a recipient of the distinguished KBA award from the Blues Foundation.  He received a 59th Grammy nomination for his work as producer and performer on Joe Louis Walker's "Everybody Wants a Piece". Mountain is an American hard rock band that formed on Long Island, New York in 1969.  Originally comprising vocalist and guitarist Leslie West, bassist/vocalist Felix Pappalardi, keyboardist Steve Knight and drummer N. D. Smart, the band broke up in 1972 and has reunited frequently since 1973, remaining active today.  Best known for their cowbell-tinged song "Mississippi Queen", as well as for their performance at the famous Woodstock Festival in 1969, Mountain is one of many bands to be commonly credited as having influenced the development of heavy metal music in the 1970s.  The groups musical style primarily consisted of hard rock, blues rock and heavy metal. No. 4 (officially stylized as № 4) is the fourth album released by American hard rock band Stone Temple Pilots, released on October 26, 1999, by Atlantic Records.  The album was a return to the band's earlier hard rock roots, while also blending elements of heavy metal, psychedelic rock, and alternative rock.  Despite the lack of promotion due to singer Scott Weiland's one-year jail sentence shortly before the album's release, "No. 4" was certified Platinum by the RIAA on August 7, 2000, and by the CRIA in August 2001.  The song "Down" was nominated for Best Hard Rock Performance at the Grammy Awards.  The album also produced one of STP's biggest hits, "Sour Girl", which charted at #78 on the "Billboard" Hot 100, their only song to appear on that chart.  The CD was originally released as a digipak, then later changed to a standard jewel case. The New York Dolls were an American hard rock band formed in New York City in 1971.  Along with the Velvet Underground and the Stooges, they were one of the first bands of the early punk rock scenes.  Although their original line-up fell apart quickly, the band's first two albums—"New York Dolls" (1973) and "Too Much Too Soon" (1974)—became among the most popular cult records in rock.  The line-up at this time comprised vocalist David Johansen, guitarist Johnny Thunders, bassist Arthur Kane, guitarist and pianist Sylvain Sylvain, and drummer Jerry Nolan; the latter two had replaced Rick Rivets and Billy Murcia, respectively, in 1972.  On stage, they donned an androgynous wardrobe, wearing high heels, eccentric hats, and satin.  Nolan described the group in 1974 as "the Dead End Kids of today". Blue Öyster Cult (often abbreviated BÖC) is an American hard rock band formed on Long Island, New York, in 1967, whose most successful work includes the hard rock and heavy metal songs "(Don't Fear) The Reaper", "Godzilla" and "Burnin' for You".  Blue Öyster Cult has sold over 24 million records worldwide, including 7 million records in the United States alone.  The band's music videos, especially "Burnin' for You", received heavy rotation on MTV when the music television network premiered in 1981, cementing the band's contribution to the development and success of the music video in modern popular culture. The Long Island AVA is an American Viticultural Area encompassing Nassau and Suffolk counties of New York, including the smaller offshore islands in those counties.  The AVA was established in 2001, over 15 years after two smaller AVAs were created at the eastern end of Long Island.  The Long Island AVA designation was promoted as a benefit for some wineries located just outside the two smaller AVAs and for wineries that wanted to create wines that use blends from vineyards in different parts of the island.  It was also developed and promoted as a consumer protection of the Long Island name; AVAs require that a minimum of 85% of the fruit used in the designated wine is grown within the borders of the region.  The "Long Island" AVA was authored by veteran Long Island winemaker Richard Olsen-Harbich who also authored the "The Hamptons, Long Island" and "North Fork of Long Island" AVAs in the mid-1980s. Step Back is an album by blues guitarist and singer Johnny Winter.  It features performances by a number of guest musicians, including Eric Clapton, Dr. John, Billy Gibbons from ZZ Top, Joe Perry from Aerosmith, Leslie West from Mountain, and Brian Setzer from the Stray Cats.  It was released by Megaforce Records on September 2, 2014. Jason Ricci (born February 3, 1974) is an American harmonica player and singer.  In addition to his solo albums, Ricci has appeared as a guest harmonica player on albums with Johnny Winter, Nick Curran, Ana Popovic, Walter Trout, Cedric Burnside, The Mannish Boys and Joe Louis Walker among others.  Ricci was named "Best Harmonica Player" at the 2010 Blues Music Awards, and also performed on Grammy winning 2014 Johnny Winter album "Step Back".  In February 2015, Ricci played at the Rock and Roll Hall of Fame with the Paul Shaffer Band, Tom Morello and Zac Brown to induct The Paul Butterfield Blues Band.  Ricci also continues touring with his band Jason Ricci and the Bad Kind as well as with other bands such as: "Harmonicon" (Sugar Blue,Billy Branch,Ricci), "JJ Appleton and Jason Ricci" and "Mark Hummel's Blues Blow Off".  In 2017 Jason Ricci and The Bad Kind signed a record deal with the Eller Soul Label and released their new album "Approved By Snakes" released June 16th 2017. AC/DC are a hard rock band formed in Sydney, Australia in 1973 by brothers Angus and Malcolm Young.  Although the band are considered pioneers of heavy metal, its members have always classified their music as "rock 'n' roll".  AC/DC underwent several line-up changes before releasing their first album, "High Voltage", in 1975.  Membership remained stable until bassist Cliff Williams replaced Mark Evans in 1977.  In 1979, the band recorded their highly successful album "Highway to Hell".  Lead singer and co-songwriter Bon Scott died on 19 February 1980, after a night of heavy alcohol consumption.  The group briefly considered disbanding, but soon ex-Geordie singer Brian Johnson was selected as Scott's replacement.  Later that year, the band released their best-selling album, "Back in Black".  The band's next album, "For Those About to Rock We Salute You", was also highly successful and was their first album to reach number one in the United States.  AC/DC declined in popularity soon after the departure of drummer Phil Rudd in 1983.  Poor record sales continued until the release of "The Razors Edge" in 1990.  Phil Rudd returned in 1994 and contributed to the band's 1995 album "Ballbreaker". " Stiff Upper Lip" was released in 2000 and was well received by critics.  The band's new album "Black Ice" was announced in June 2008 and was released on October 20, 2008.  The album's first single, "Rock 'N Roll Train", earned AC/DC a Grammy nomination for Best Rock Group or Duo with Vocals.  Another "Black Ice" track, "War Machine," gained AC/DC their first Grammy Award win, for Best Hard Rock Performance.
Answer: Leslie West