Between 1966 and 1967 Curtis joined The Ramong Sound. He joined the group after hearing from his uncle that Ramong, Raymond Morrison, the lead singer of the group, was looking for backing singers. Curtis initially had very limited singing experience, only singing with his uncle when he came around the house with the guitar. After losing their original lead singer, the band took on board Arthur Brown temporarily, and went through a few name changes before they became The Foundations Arthur Brown stated in an interview that in his time with the group, he enjoyed singing with Curtis. They both sang separately as well as doing some duets. The group emerged in January 1967 with Curtis as their lead singer. The Foundations would go on to have worldwide hits with "Baby Now That I've Found You" and "Build Me Up Buttercup". Curtis is the lead voice on their hits "Baby Now That I've Found You", "Back on My Feet Again", and "Any Old Time (You're Lonely and Sad)".