Some context: Sonny & Cher were an American pop music duo, actors, singers and entertainers made up of husband-and-wife Sonny and Cher Bono in the 1960s and 1970s. The couple started their career in the mid-1960s as R&B backing singers for record producer Phil Spector. The pair first achieved fame with two hit songs in 1965, "Baby Don't Go" and "I Got You Babe". Signing with Atco/Atlantic Records, they released three studio albums in the late 1960s, as well as the soundtrack recordings for two unsuccessful movies, Good Times and Chastity, with Cher contributing vocals to one cut, "Chastity's Song (Band of Thieves)" .
In 1967 Sonny and Cher released their third album, In Case You're In Love. It peaked at number 45 in the U.S. charts. It contained two hit singles, both written by Bono, "The Beat Goes On" (No. 6 on the Billboard Hot 100) and "Little Man" (No. 21 on the Billboard Hot 100), that peaked at the number one in five European countries.  In an attempt to capitalize on the duo's initial success, Bono speedily arranged a film project for the duo to star in. But the 1967 feature, Good Times, was a major bomb, despite the efforts of fledgling director William Friedkin and co-star George Sanders. After Good Times flopped in 1968, Columbia Pictures immediately sold rights to their intended follow-up film Speedway to MGM. The couple were replaced by Elvis Presley and Nancy Sinatra. In 1969, another film, Chastity, starring Cher, written and produced by Sonny, was also a commercial bomb.  Sonny and Cher's career had stalled by 1968 as album sales quickly dried up. Their gentle, easy-listening pop sound and drug-free life had become unpopular in an era increasingly consumed with the psychedelic rock of the evolving landscape of American pop culture during the late 1960s.  Bono decided to forge ahead, carving a new career for the duo in Las Vegas resorts, where they sharpened their public persona with Cher as the wise-cracking singer, and Bono as the good-natured recipient of her insults. In reality, Bono controlled every aspect of their act, from the musical arrangements to the joke-writing. While success was slow to come, their luck improved when network TV talent scouts attended a show, noting their potential appeal for a variety series.  Sonny and Cher also welcomed their first child, Chastity Sun Bono, born on March 4, 1969.
Did they have an act they performed?
A: Cher as the wise-cracking singer, and Bono as the good-natured recipient of her insults.

Some context: A Funny Thing Happened on the Way to the Forum is a musical with music and lyrics by Stephen Sondheim and book by Burt Shevelove and Larry Gelbart. Inspired by the farces of the ancient Roman playwright Plautus (251-183 BC), specifically Pseudolus, Miles Gloriosus, and Mostellaria, the musical tells the bawdy story of a slave named Pseudolus and his attempts to win his freedom by helping his young master woo the girl next door. The plot displays many classic elements of farce, including puns, the slamming of doors, cases of mistaken identity (frequently involving characters disguising themselves as one another), and satirical comments on social class. The title derives from a line often used by vaudeville comedians to begin a story: "A funny thing happened on the way to the theater".
A Funny Thing Happened on the Way to the Forum opened on Broadway on May 8, 1962, at the Alvin Theatre, and then transferred to the Mark Hellinger Theatre and the Majestic Theatre, where the show closed on August 29, 1964, after 964 performances and 8 previews.  The show's creators originally wanted Phil Silvers in the lead role of Pseudolus, but he turned them down, allegedly because he would have to perform onstage without his glasses, and his vision was so poor that he feared tripping into the orchestra pit. He is also quoted as turning down the role for being "Sgt. Bilko in a toga". (Silvers eventually played the role -- wearing his glasses -- in a 1972 revival. In the film, he played Marcus Lycus.) Milton Berle also passed on the role. Eventually, Zero Mostel was cast.  During the out of town pre-Broadway tryouts the show was attracting little business and not playing well. Jerome Robbins was called in to give advice and make changes. The biggest change Robbins made was a new opening number to replace "Love Is in the Air" and introduce the show as a bawdy, wild comedy. Stephen Sondheim wrote the song "Comedy Tonight" for this new opening. From that point on, the show was a success.  It was directed by George Abbott and produced by Hal Prince, with choreography by Jack Cole and uncredited staging and choreography by Robbins. The scenic and costume design was by Tony Walton. This wardrobe is on display at the Costume World Broadway Collection in Pompano Beach, Florida. The lighting design was by Jean Rosenthal. Along with Mostel, the musical featured a cast of seasoned performers, including Jack Gilford (Mostel's friend and fellow blacklist member), David Burns, John Carradine, Ruth Kobart, and Raymond Walburn. The young lovers were played by Brian Davies and Preshy Marker. Karen Black, originally cast as the ingenue, was replaced out of town.  The show won several Tony Awards: Best Musical, Best Actor, Best Supporting Actor (Burns), Best Book, and Best Director. The score, however, was coolly received; it was Sondheim's first musical on Broadway in which he wrote both the music and lyrics, and did not earn a nomination for Best Original Score.
What other achievements were there?
A:
The biggest change Robbins made was a new opening number to replace "Love Is in the Air" and introduce the show as a bawdy, wild comedy.