“Single-note practice is of limited benefit to a violinist for intonation, since it does not have a fixed pitch from which to measure. Consequently, a violinist may practice single-note scales for years and never really develop a precise ear. […] The single-note scale system is inefficient, since there is no way of checking the intonation from note to note. Intonation, therefore, must be based on a chordal-key relationship.”
— Ruggiero Ricci, Left-Hand Violin Technique 3 years ago
