anonymous
4 books with manuscript music for viola bastarda, inventoried as
#166: 2 Viola Bastardbuch geschrieben
#167: 1 dito buch mit noten, darinnen etliche galliard, paduanen etc. geschrieben
#168: Ein Viola Bastardbuch
lost
From the inventory of the possessions of Johann Georg Beck, Breslavia, 1638. The inventory itself was lost during World War II, but the text is reproduced and discussed in Brooks, The Emergence of the Violin (see bibliography) and earlier publications.
Joëlle Morton, Redefining the Viola Bastarda: A Most Spurious Subject, «The Viola da Gamba Society Journal», 8, 2014, pp. 1-64. http://vdgs.org.uk/journal/Vol-08.pdf