Warren Entner has the distinction of having been one of the original members of the Grass Roots -- though, owing to the confusing early history of that group, he was not one of the "original" Grass Roots. Born in Boston in 1944, he reached his teens in 1957 amid rock & roll's second wave -- by the early '60s he was playing guitar and singing, and crossed paths with California-born Creed Bratton, another singer/guitarist, and the two traveled around Europe and the Middle East as a performing duo. After a taste of working together in a band in Israel, they headed back to the United States, where Bratton later approached Entner about working together again -- out of that idea came the 13th Floor, with Rick Coonce on drums and, eventually, Rob Grill as bassist. Entner played keyboards as well as rhythm guitar, and also contributed some 12-string work, and he and Grill (and, to a lesser degree, Bratton) traded off lead vocals and choruses.
The 13th Floor were signed to Dunhill Records in an arrangement that required them to assume the identity of the Grass Roots, a name associated with a string of previously issued singles and one album, produced and mostly written (and occasionally sung) by the composer/producer team of P.F. Sloan and Steve Barri (who had previously failed in their efforts to get another band, the Bedouins, to take on the role of the Grass Roots). With Entner, Grill, Bratton, and Coonce, the effort succeeded, however, and within a few months the Grass Roots were riding high on the charts with "Let's Live for Today," a perfectly crafted folk-rock-pop single that heavily featured Grill and Entner's vocals. Although they weren't known for their originals, all four of the members composed songs, and Grill and Entner were easily the most prolific among them, sharing many copyrights as well as earning places on various single B-sides. Entner was also highly visible in their performances, usually out in front with Grill in their television appearances and on-stage.
And while their records, especially in the early days, relied heavily on contributions from outside studio musicians, the surviving evidence of the group's live performances demonstrates that the musicianship of Entner and the other bandmembers was perfectly fine -- and even occasionally elegant -- and well suited to the needs of an AM radio-oriented pop band. The group's various hits, including "Midnight Confessions" (which also showcased Entner's organ playing) and "The River Is Wide," would keep him in the spotlight (alongside Grill) well into the 1970s, long after Bratton and Coonce had left the lineup. Entner remained with the band until 1973, leaving the Grass Roots after the Alotta Mileage album. He was involved on the production side of some of the group's later work on which he participated, and later went into music management. In more recent years, he has represented such acts as Rage Against the Machine and Faith No More.