Alexis Merizalde Knapp (born July 31, 1989) is an American actress and singer.
 She is known for her role as Stacie Conrad in the musical films "Pitch Perfect" (2012) , "Pitch Perfect 2" (2015) and the upcoming "Pitch Perfect 3".
 She is also known for her role of Alexis in the party film "Project X" (2012), and her role on the first season of the TBS comedy "Ground Floor".
Kelley Alice Jakle (born June 27, 1989) is an American actress and singer-songwriter.
 She is best known for her role as Jessica in "Pitch Perfect" (2012) and its sequel "Pitch Perfect 2" (2015).
 She is also known for her appearances on the first and second seasons of "The Sing-Off" in 2009 and 2010.
Patricia "Trish" Sie (née Kulash) is an American film and music video director, best known for directing the films "" (2014) and "Pitch Perfect 3" (2017), as well as music videos, particularly for the alternative rock band OK Go.
 She has worked in film, television, commercials, music videos, stage, children's entertainment and ballroom DanceSport.
Pitch Perfect 3 is an upcoming American musical comedy film directed by Trish Sie and written by Kay Cannon.
 A sequel to "Pitch Perfect 2" (2015) and the third and final installment in the "Pitch Perfect" trilogy, the film will star Anna Kendrick, Anna Camp, Rebel Wilson, Brittany Snow, Hailee Steinfeld, Alexis Knapp, Ester Dean, Hana Mae Lee, Chrissie Fit, Kelley Jakle and Shelley Regner, with Elizabeth Banks and John Michael Higgins.
 The film is scheduled to be released on December 22, 2017.
Pitch Perfect 2 is a 2015 American musical comedy film directed and co-produced by Elizabeth Banks and written by Kay Cannon.
 It is a sequel to the 2012 film "Pitch Perfect" and the second installment in the "Pitch Perfect" series.
 The film centers on the fictional Barden University and The Bellas, an all-female a cappella singing group.
 The film features an ensemble cast, including Anna Kendrick, Rebel Wilson, Hailee Steinfeld, Brittany Snow, Alexis Knapp, Hana Mae Lee, Ester Dean, Chrissie Fit, Kelley Jakle and Shelley Regner as The Bellas.
 It was released on May 15, 2015 by Universal Pictures.
Skylar Astin Lipstein (born September 23, 1987), known professionally as Skylar Astin, is an American actor and singer.
 He became known for portraying Jesse Swanson in the musical films "Pitch Perfect" (2012) and "Pitch Perfect 2" (2015).
 He was also in the original cast of the Broadway musical "Spring Awakening", and has since appeared in films such as "Hamlet 2" (2008), "Taking Woodstock" (2009), "Cavemen" (2013), and "21 & Over" (2013).
Anna Ragsdale Camp (born September 27, 1982) is an American actress and singer.
 She is known for her role as Sarah Newlin in "True Blood", and her recurring roles in "Mad Men", "The Good Wife", and "The Mindy Project".
 She is also known for her role as Aubrey Posen in "Pitch Perfect" (2012), "Pitch Perfect 2" (2015), and the upcoming "Pitch Perfect 3" (2017).
 She made her Broadway debut in the 2008 production of "A Country House" and played Jill Mason in the 2008 Broadway revival of "Equus".
 In 2012, she was nominated for a Drama Desk Award for her performance in the Off-Broadway play "All New People".
 Camp played Jane Hollander, a researcher for the fictitious "News of the Week" magazine in the Amazon series "Good Girls Revolt."
 She also had a role in the 2011 film "The Help".
Pitch Perfect is a series of musical comedy films created by Kay Cannon, loosely based on the non-fiction book "Pitch Perfect: The Quest for Collegiate a Cappella Glory" by Mickey Rapkin.
 Jason Moore directed the first film, and Elizabeth Banks directed the second, with the upcoming third installment set to be released on December 22, 2017.
 Paul Brooks, Max Handelman, and Banks produced the films.
 It features an ensemble cast, including Anna Kendrick, Rebel Wilson, Anna Camp, Brittany Snow, Skylar Astin, Adam DeVine, Ben Platt, Alexis Knapp, Hana Mae Lee, Ester Dean, Hailee Steinfeld, Chrissie Fit, Katey Sagal, John Michael Higgins, and Banks.
 The series is distributed by Universal Pictures.
Shelley Anne Regner (born December 21, 1988) is an American actress and singer known for her role as Ashley in the musical films "Pitch Perfect" (2012) and its sequel "Pitch Perfect 2" (2015).
 She will be returning for the third installment, "Pitch Perfect 3" (2017).
Hailee Steinfeld (born December 11, 1996) is an American actress and singer.
 She first became known for her portrayal of Mattie Ross in "True Grit" (2010), which earned her an Academy Award nomination.
 Thereafter, she appeared as Petra Arkanian in "Ender's Game" (2013), Juliet Capulet in "Romeo & Juliet" (2013), Violet Mulligan in "Begin Again" (2013), Zooey Renner in "3 Days to Kill" (2014), Emily Junk in "Pitch Perfect 2" (2015) and "Pitch Perfect 3" (2017), and Nadine Franklin in "The Edge of Seventeen" (2016), the last for which she received a Golden Globe Award nomination.

Question: Pitch Perfect 3 includes as part of the cast the actress and singer-songwriter who appeared on the first and second seasons of what television show?
Answer: "The Sing-Off"