George "Shadow" Morton, the visionary Brill Building songwriter and producer who also worked with rock artists including Iron Butterfly and Vanilla Fudge, has died at age 72. As of press time, the cause of death has not been disclosed.

Along with Phil Spector, with whose work his is often compared and confused, Morton is best remembered for helping popularize girl groups in the '60s. He is most closely associated with the Shangri-Las, whom he discovered and helped fashion their biggest hits, 'Remember (Walking In The Sand),' 'Leader of the Pack' and 'Give Him a Great Big Kiss.'

As a staff producer for Jerry Leiber and Mike Stoller's Red Bird Records, Morton's songs for the Shangri-Las came to life in the studio. He took advantage of the latest technology and often added orchestration and sound effects, most famously the motorcycles on 'Leader of the Pack,' which hit No.1 in 1964, to create a new sub-genre of pop: the teen melodrama.

Following the demise of Red Bird, Morton went on to discover and produce singer-songwriter Janis Ian and the Vanilla Fudge, including their debut, which featured their hit psychedelicized take on the Supremes' 'You Keep Me Hanging On.' In 1974, he produced 'Too Much Too Soon,' the second album by proto-punks New York Dolls.

A native of Hicksville, N.Y., Morton was a childhood friend of Ellie Greenwich, who, along with her future husband Jeff Barry (the three are pictured above, with Morton on the right), wrote dozens of pop classics throughout the 1960s. He was inducted into the Long Island Music Hall of Fame in 2006.

Watch the Shangri-Las Perform 'Remember (Walking in the Sand)'

Hear Aerosmith Perform 'Remember (Walking in the Sand)'