Guitar,Instrumental Duet,Viola - Level 4 - Digital Download SKU: A0.1357811 Composed by Spanish Popular Song. Arranged by Guilherme Facchetti. Classical,Folk,Latin,Multicultural,Traditional,World. 10 pages. Guilherme Facchetti #942316. Published by Guilherme Facchetti (A0.1357811). This arrangement of “Los Cuatro Muleros” for Viola and Classical Guitar is a free artistic recreation, based on the phonographic informations contained in the performance of AgustĂn CastellĂłn Campos Sabicas (1912 –1990), broadcast on TVE in the year 1968.