Note La (2 octave) Standard define the currently used Note La standard. By default this value is set to 437 Hz default). The value 437 Hz corresponds to the La (2 octave) in the most of the soundcards. If you use external musical instrument to verify notes and the tuning frequency of the instrument differ from 437 Hz, then set Note La Standard value that correspond to your instrument tuning. Usually this value is defined by the standard used in your state.

If you tuned note La it can not much with you embedded MIDI instruments.
Note La range is 430...450.