 He collaborated with many of the leading librettists and lyricists of his era, including George Grossmith Jr., Guy Bolton, P. G. Wodehouse, Otto Harbach, Oscar Hammerstein II, Dorothy Fields, Johnny Mercer, Ira Gershwin and Yip Harburg.A native New Yorker, Kern created dozens of Broadway musicals and Hollywood films in a career that lasted for more than four decades.His musical innovations, such as 4/4 dance rhythms and the employment of syncopation and jazz progressions, built on, rather than rejected, earlier musical theatre tradition.