Playing and singing in many orchestras until the end of the '60s, Ersen's faith turned when he met Cem Karaca in person. A newborn star in Turkish rock scene, Karaca was managing Bunalimlar at the time and offered Ersen an opportunity to record. His first single, "Olvido — Ak Guvercin," was released in 1969 and featured hypnotic guitar work from Unol Buyukgonenc. A year later, Ersen replaced Aziz Azmet of Mogollar to lead the band. The collaboration was very short, as Mogollar headed to France, so Ersen joined forces with another Anadolu pop band, Uc Hurel. Ersen's early singles were mostly Spanish-influenced, but he later evolved into a unique blend of Turkish folk and Western progressive themes. His breakthrough single, "Kozan Dagi," was released in 1972. "Sor Kendine," released that same year, was an incredible show of talent, and it's still one of the pivotal points of his career.
He later joined Mogollar once again, played with Kardaslar, and at last formed his well-known band Dadaslar. Being a group of talented musicians of the present scene, Dadaslar could never maintain a stable line-up; however, they supplied the necessary background for one of the most important figures in the Anadolu pop/rock scene. Ersen released "Cakmagi Çak," "Yine Seni Taninm," "Bir Ayrilik Bir Yoksulluk Bir Olum," "Uc Kiz Bir Ana," "Ne Sevdigin Belli Ne Sevmedigin," and "Ekmek Parasi," among other singles, until the end of 1978. Following the tendency of the Turkish music market in the '80s Ersen laid aside his band and continued his career alone. Like the rest of his fellow Turkish musicians, he was also forced to choose a side in the political turmoil of the day. Despite trying not to reveal clear political beliefs, he was right wing-oriented, and after the Army took control of the government, he was disrespected by many musicians and fans. He played and recorded for the Army and the governmental media, TRT.
Hatamizi Bilmeden Cekiyoruz (1980) and Anadolu Pop (1983) were the last of his musically rich albums. Leaning toward a more poppy and shallow sound, Ersen faded away with his last album of the '90s, Ersen Ustadan Kuru Fasulye in 1993. After a nine-year hiatus, Ersen returned to the music business with Ersen Mevlana Gibi. The album, finding Ersen in a more mystical and spiritual form, failed to draw attention, just like the following year's Donemem. In 2007, Ersen ve Dadaslar re-recorded five of their classic tunes and released them as an album called Ersen ve Dadaslar Yeniden (1973-2007).