Sagreras wrote a famous guitar method, Las Lecciones de Guitarra in seven volumes, also known as Sagreras 1-7. This method provides instruction in playing the guitar from beginner to advanced level, the method is still in use.
Etude 37 is a surprisingly pleasant South American-sounding piece that you can play at a comfortable pace, obviously after thorough practice. The timing of the rests is one of the challenges of the piece.
In the first version that I encountered, it turned out that the legato’s that Sagreras had prescribed were omitted. With legato’s the piece is a much bigger challenge. I will meet the challenge, the new version is true to Sagreras ’original.