Just finished
Early American vocal groups: 100 years of harmony 1850-1950 - Friedman & Gribin
An interesting read which I found recommended on Unca Marvy's R&B page. No wonder, a lot of the references come from him
Its a little light on history - only 80/90 pages of history. The meat of the book is the Groupography, listing all the groups they can trace, their personnel, location, date, recording activity where known. There's also a discography, which I passed over finding that, not only were the groups in alphabetical order (not unreasonable) but for each group, the songs were in alphabetical order!!!
The most fascinating part of the book for me was that dealing with groups' appearances on the covers of sheet music and postcards. I could have done with more of that. The postcard of The Breakfast Four, who appeared on Westinghouse stations WBZ-WBZA around 1940, showing them sitting around a breakfast table in dressing gowns, is wonderful.
Good bibliography (though Allen Lowe not mentioned) and some nice compilation CDs of old records listed.
Not essential reading, but not uninteresting.
MG