Question: The Sign o' the Times was a tour by an American songwriter that won how many Grammy Awards?
Context: Charles Chalmers is a saxophonist, session musician, backup singer, songwriter and producer.  He has written several hit songs for many recording artists, and has also arranged & performed on many grammy winning recordings.  Seven of those recordings are in the Grammy Hall of Fame : Al Green's "Let's Stay together"; Aretha Franklin's "Respect," "Chain of Fools" & "Natural Woman"; Dusty Springfield's "Son of a Preacher Man"; and Wilson Pickett's "Mustang Sally" and "Land of a Thousand Dances."  He also holds an Album of the Century award for his work on Aretha Franklin's, "I Ain't Never Loved a Man the Way that I Love You." Juan Luis Guerra Seijas (born June 7, 1957), known professionally as Juan Luis Guerra, is a Dominican singer, songwriter, composer, and producer.  He has sold over 30 million records, and has won numerous awards including 18 Latin Grammy Awards, two Grammy Awards, and two Latin Billboard Music Awards.  Guerra won 3 Latin Grammy Awards in 2010, including Album of the Year.  In 2012, he won the Latin Grammy Award for Producer of the Year. Kristen Anderson-Lopez is an American songwriter.  Anderson-Lopez, along with her husband Robert Lopez and Henry Jackman, wrote and produced music for the 2011 Disney film "Winnie the Pooh", for which they were nominated for an Annie Award for Best Music in a Feature Production.  She also provided the voice of Kanga in the film.  Additionally, she wrote songs for a Walt Disney World production of "Finding Nemo – The Musical".  She and her husband also wrote the songs for Disney's "Frozen" including "Let It Go", for which they won the Academy Award for Best Original Song at the 86th Academy Awards and two Grammy Awards at the 57th Annual Grammy Awards. Gordon Goodwin's Big Phat Band, or simply The Big Phat Band, is an 18-piece jazz orchestra that combines the big band swing of the 1930s and 1940s with contemporary music such as funk and jazz fusion.  The band is led by Gordon Goodwin, who arranges, composes, plays piano and saxophone.  Since its origin, the Big Phat Band has received several Grammy Awards and many Grammy nominations. The Grammy Awards have been held in many prestigious locations.  In 1971 the Grammy Awards had its first live telecast and therefore had its own sole venue each year for the telecast.  From 1963 to 1970 the Academy aired a TV special annually called "The Best On Record" which highlighted the awards dinners.  Since 2000, the Grammy Awards have been held in the Staples Center located in Downtown Los Angeles. Whitney Houston is one of the most successful female singers of all time.  Her accomplishments have been recognized with six competitive Grammy Awards, and one Grammy Hall of Fame Award, giving her a total of 7 Grammy Awards.  Though she has been nominated twenty-six times and for two times songs performed by her were nominated for Song of the Year.  She earned her first Grammy, Best Pop Vocal Performance, Female in 1986, and was honored with two general field Grammys: Album of the Year for "" and Record of the Year for "I Will Always Love You" at its 36th ceremonies in 1994.  Below is a list of awards for which she has been nominated and those that she won (the winner in each category has ★ mark). Paul Richard Epworth (born 25 July 1974 in Bishop's Stortford, Hertfordshire) is an English music producer, musician, and songwriter.  His production and writing credits include Adele, Rihanna, and Maxïmo Park amongst many others.  On 12 February 2012 at the 54th Grammy Awards, Epworth won four Grammy Awards for Producer of the Year, Album of the Year (Adele's "21"), and Song of the Year and Record of the Year (for "Rolling in the Deep").  He won the Academy Award for Best Original Song alongside Adele, for "Skyfall".  His sister Mary Epworth is a singer and songwriter.  He is a member of the Music Producers Guild.  He also has a record label, Wolf Tone, whose artists include Glass Animals, Rosie Lowe and Plaitum.  He has won 'Producer of the Year' at the BRIT Awards three times, the most recent in 2015.  At the 59th Grammy Awards in 2017, Epworth won a Grammy for Album of the Year for his work on Adele's 25". Robert Glasper (born April 6, 1978, in Houston, Texas) is an American pianist and record producer.  He has been nominated for 6 Grammys, has won 3 Grammy Awards and is currently nominated for an Emmy Award.  His 2012 album "Black Radio" won the Grammy Award for Best R&B Album at the 55th Grammy Awards.  His 2014 album "Black Radio 2" won the Grammy Award for Best Traditional R&B Performance at the 56th Grammy Awards.  The song "These Walls" from Kendrick Lamar's album "To Pimp A Butterfly" won Best Rap/Sung Collaboration at the 57th Grammy Awards, on which Glasper plays keys.  The soundtrack for the film "Miles Ahead" won Best Soundtrack Compilation at the 58th Grammy Awards, for which Glasper was a producer.  The song "Letter To The Free", written with Common, is nominated for an Emmy Award for Best Original Song in the Ava Duvernay documentary film "13th" (Netflix) at the 2017 Emmys. The Sign o' the Times Tour was a European tour by Prince.  It was the first tour after the split with The Revolution.  As Prince's record sales were doing better in the European market than at home in the United States, Prince chose not to continue the tour into the United States after the European tour, as he was ready to get back into the studio and start a new project. Prince Rogers Nelson (June 7, 1958 – April 21, 2016) was an American singer-songwriter, multi-instrumentalist, and record producer.  He was a musical innovator who was known for his eclectic work, flamboyant stage presence, extravagant dress and makeup, and wide vocal range.  His music integrates a wide variety of styles, including funk, rock, R&B, new wave, soul, psychedelia, and pop.  He has sold over 100 million records worldwide, making him one of the best-selling music artists of all time.  He won seven Grammy Awards, an American Music Award, a Golden Globe Award, and an Academy Award for the film "Purple Rain".  He was inducted into the Rock and Roll Hall of Fame in 2004, his first year of eligibility.
Answer: seven