Music Production Calc: Fret Note Lookup

Use this endpoint when you need precise note name, MIDI number, or frequency data for a specific fret and string position on a guitar, bass, ukulele, or violin — especially when alternate tunings or non-standard A4 reference pitches are involved. It is ideal for music production tools, fretboard educators, MIDI mapping assistants, and tuning analysis workflows where instrument-specific string/fret lookup is required rather than general music theory computation.

• Missing required parameters (instrument, string, fret) returns a validation error
• Fret number out of range 0–24 or string number out of valid range for the instrument returns an error
• Invalid instrument name (not guitar, bass, ukulele, or violin) returns an error
• A4 reference pitch outside 400–480 Hz range returns an error
• Tuning offset outside -12 to 12 semitones returns an error