Richard Widdess. Dāphā: Sacred Singing in a South Asian City. Music, Performance and Meaning in Bhaktapur, Nepal. SOAS Musicology Series. Ashgate, December 2013 [official site]. 378 pages (w/ “50 b&w illustrations, 50 music examples and 1 map”). ISBN 978-1-4094-6601-7.
From the blurb
Dāphā, or dāphā bhajan, is a genre of Hindu-Buddhist devotional singing, performed by male, non-professional musicians of the farmer and other castes belonging to the Newar ethnic group, in the towns and villages of the Kathmandu Valley, Nepal. The songs, their texts, and their characteristic responsorial performance-style represent an extension of pan-South Asian traditions of rāga- and tāla-based devotional song, but at the same time embody distinctive characteristics of Newar culture.