A Dictionary of Music and Musicians/La
LA, the syllable used in solmisation for the sixth note in the scale, possibly derived by Guido from the sixth line of the well-known hymn to S. John—'Labii reatum.' It is used by the French and Italians as a synonym for A (the sixth note of the scale of C)—'Sinfonie en la de Beethoven,' and they speak of the second string of the violin as 'corde en la.' 'La bémol' is A flat.
The number of vibrations per second for the A in the treble stave is—Paris diapason 435, London Philharmonic pitch 454. The A proposed by the Society of Arts, and actually in use (1879) at H.M. Opera, 444 (eq. temp.)[ G. ]