Osvaldo Ulloa has been played on NTS in shows including ARRHYTHMIA, featured first on 19 September 2023. Songs played include Versos Por José.

Don Osvaldo 'Chosto' Ulloa (Osvaldo del Tránsito Ulloa Lobos, b. 1936), is the eldest of a small community of guitarrón players of Pirque, a rural community 20 kilometres south of Santiago, Chile. He was born in fundo El Principal, where he has lived all his life as a labourer and musician.

The origin of the guitarrón, a 25-stringed guitar unique to Chile, is shrouded in mystery. The guitarroneros use it in their Canto a lo poeta (Poet’s Song), which encompasses the Canto a lo Divino (religious-themed songs) and Canto a lo Humano (songs of everyday life). Every new instrument is baptised and given a name. The tradition only came to wider attention with the publication of the recording Guitarroneros de Pirque (2000), which showcases the work of Chosto Ulloa and fellow musicians.