Frank French, from San Francisco, California, will appear as Louis Moreau Gottachalk at the Spring Chautauqua in Tulsa.   French has performed in chautauquas as Gottschalk all across the U.S.   In addition to his expertise in Gottschalk, French is well know as a ragtime and Latin-flavored pianist and composer.   He has composed many pieces utilizing Latin rhythms, some of which are incorporated into his ragtime compositions.   His most famous ragtime piece is Belle Of Louisville which is regarded by many as the "Maple Leaf Rag" of the twentieth century.   He has appeared numerous times at all the ragtime festivals across the U.S. and has collaborated with Scott Kirby and others for many duo-piano ragtime performances.   He appeared with Kirby in Tulsa in two sold out performances at the Philbrook Museum in 1998.