Triste Nº.3 composed by Julián Aguirre and arranged by José Luis Merlin for cello and guitar. There is also a flute / violin and guitar version available.

WATCH VIDEO José Luis Merlin(guitar) and Ekaterina Chernova (cello) HERE:

https://www.youtube.com/watch?v=pKXUa7XAggA&ab_channel=EvgeniyaKirilyuk