There is a total of 21193 clues beginning with si
- Singer of the 1959 hit "Don't You Know"
- Singer of the 1961 #1 song found in the starts of 16-, 23-, 37- and 48-Across
- Singer of the 1962 hit "Mashed Potato Time"
- Singer of the 1962 hit "The Wanderer"
- Singer of the 1965 hit "Lemon Tree"
- Singer of the 1966 hit Motown ballad "What Becomes of the Brokenhearted"
- Singer of the 1967 hit "California Nights"
- Singer of the 1969 #1 hit 'Dizzy'
- Singer of the 1974 hit "I've Got the Music in Me"
- Singer of the 1975 #1 hit "Before the Next Teardrop Falls"
- Singer of the 1975 #1 hit "Laughter in the Rain"
- Singer of the 1984 hit "99 Luftballons"
- Singer of the 1984 hit '99 Luftballons'
- Singer of the 1987 #1 country hit "Do Ya"
- Singer of the 1989 #1 hit "Opposites Attract"
- Singer of the 1991 hit "Wicked Game"
- Singer of the 1992 hit "Crucify"
- Singer of the 1994 #1 hit "Stay"
- Singer of the 2001 hit "Thankyou"
- Singer of the 2002 #2 hit "Beautiful"
- Singer of the 2008 #1 hit "Bleeding Love"
- Singer of the 2010 #1 hit "Rude Boy"
- Singer of the 2011 #1 hit "Someone Like You"
- Singer of the 2011 hit "Someone Like You"
- Singer of the 2011 No 1 hit "Lucky Now"
- Singer of the 2012 #1 hit "Somebody That I Used to Know"
- Singer of the 2012 Bond film theme
- Singer of the 2015 #1 hit "Cheerleader"
- Singer of the 2015 #1 hit "Hello"
- Singer of the 2016 #1 hit "Cheap Thrills"
- Singer of the 2016 #1 hit "Pillowtalk"
- Singer of the 2018 No 1 hit "Without Me"
- Singer of the 2019 #1 hit "Señorita"
- Singer of the album "25"
- Singer of the anthem "Hatikvah" ("The Hope")
- Singer of the anthem "Sång till Norden"
- Singer of the aria "Dio! mi potevi scagliar"
- Singer of the aria "Largo al factotum"
- Singer of the aria "Ora e per sempre addio"
- Singer of the children's album "Camp Lisa"
- Singer of the cinema
- Singer of the feel-good a cappella #1 hit whose title begins the answers to starred clues
- Singer of the first words of 18-, 25- and 48-Across
- Singer of the Gallic version of "Who's Sorry Now"?
- Singer of the Leoncavallo aria "Vesti la giubba"
- Singer of the lyric formed by the ends of the answers to the four italicized clues
- Singer of the movies
- Singer of the multimillion-selling album "Watermark"
- Singer of the No 1 hit "Foolish"
- Singer of the Oscar-nominated "May It Be"
- Singer of the Oscar-nominated song "May It Be"
- Singer of the screen
- Singer of the song "Shadowland" in "The Lion King"
- Singer of the song referenced in 7-Down
- Singer of the titular song in 2012's "Skyfall"
- Singer of the Top 10 hit "Walk on Water"
- Singer of the Wagner aria "Liebestod"
- Singer of Tolkien-language lyrics
- Singer of “Despacito,” which has more than eight billion views on YouTube
- Singer Okasec of The Cars
- Singer Oleta
- Singer on "25"
- Singer on "The Continuing Story of Bungalow Bill"
- Singer on a 2007 Black Heritage postage stamp, familiarly
- Singer on a 50-kronor note
- Singer on a South American gig?
- Singer on Canada's Walk of Fame since 2005
- Singer on day three of 1969's Woodstock
- Singer on half the 1984 album "Milk and Honey"
- Singer on Sunday
- Singer on the "Slumdog Millionaire" soundtrack
- Singer on the 50 kronor note
- Singer on the album "End of the Century"
- Singer on the album "Live Peace in Toronto 1969"
- Singer on the album "The Voice of the Sparrow"
- Singer on the big screen
- Singer on the go?
- Singer on the soundtrack of Disney's "Lady and the Tramp"
- Singer on the strand?
- Singer on “Give Peace a Chance”
- Singer once married to Ernest Borgnine
- Singer once married to Pamela Anderson
- Singer Ono
- Singer or "Mean Girls" character Janis
- Singer or actor's helper
- Singer or bearer
- Singer or color
- Singer or dancer, eg
- Singer or Italian lake
- Singer or Petty
- Singer or Stern
- Singer Ora
- Singer Ora with three solo #1 hits in Britain
- Singer Orbison
- Singer Orbison/politician Gore merger
- Singer Orlando
- Singer Orton and golfer Daniel
- Singer Osmond
- Singer Page
- Singer Page or LaBelle