As it turns out, there are so many that author Ken Wlaschin has easily filled a 388 page book documenting the sheet music, films and recordings through which these songs found their way into the world. The book is The Silent Cinema in Song, 1896 - 1929. It was recently released by McFarland.
And of course, the one and only Louise Brooks is including in this recommended new book. To find out more, check out my own just published article on The Silent Cinema in Song, 1896 - 1929 at examiner.com. I write on silent film topics for the website. The book itself is available on-line and at better bookstores.