Haven Gillespie has a big influence on Brian's music, among others songwriters;
He's a really talented composer and lyricist who wrote a bunch of classics and worked for famous artists.
Well known for Christmas songs, "Santa Claus Is Coming To Town", he often worked with his collaborator Beasley Smith,
"Old Man River", "The Old Master Painter", "That Lucky Old Sun"...
more infos:
http://en.wikipedia.org/wiki/Haven_Gillespie