Baskin and Gonzalez continued to write new material, and came up with "Little Girl", which the band recorded for Hush Records in San Francisco in January 1966. It became a regional hit after San Jose radio stations latched onto it, attracting the attention of executives at Bell Records in New York, who released it nationally and offered the group a contract for an album. Replacing Ray with guitarist Jim Sawyers, they wrote and recorded the LP in three weeks, and began a national tour appearing with other hit acts such as the Young Rascals, the Yardbirds, and the Rolling Stones. "Little Girl" reached the US national pop charts in June 1966, peaking at #8.
In an attempt to sustain their success, the band released three more singles, but none charted. Duckworth was then drafted, other members began to drop out, and the group disbanded in 1970. Baskin worked as a studio musician and arranger in Hollywood before turning to country music later in the decade.
"Little Girl" was later recorded by other artists, including Dwight Yoakam and R.E.M. played the song as part of its early live sets. The song was also recognized by the Rock and Roll Hall of Fame Museum, where it is on permanent rotation. In 1990, Baskin, Gonzalez and Duckworth reformed the band, which continues to perform occasionally. In 2005, Larry Ray rejoined the band.
In 2006, the Syndicate of Sound was in the first class of inductees into the San Jose Rocks Hall of Fame.