Is it necessary to learn the notes on the fretboard?
I grew up playing piano, so the keyboard is my reference. Years later, learning the fretboard has been less about learning which string/fret combination sounds a given note, but instead, given a certain chord:
1. where is the root of that chord, and with that as my anchor...
2. where is the 3rd, 5th, and 7th of that chord? Only once I can easily find those three intervals...
3. where is the 9th, 11th, and 13th. Finally, the sharps/flats of all of the above.
When it comes to organizing all of this across the fretboard, I've found the heptatonic approach to the fretboard to make the most sense and the most economical. YMMV.
Agreed that learning intervals and chord tone degrees is important. It is indeed supported by having familiarity with the underlying notes since they comprise the chords and scales.
Learning the fretboard helps players to find chords and chord inversions further up the neck. For example, the player knows they can move the E shape to the barre A position, which preserves all of the interval relationships from a new root.
Knowing the fretboard notes is a bit like playing in daylight rather than campfire darkness.
I grew up playing piano, so the keyboard is my reference. Years later, learning the fretboard has been less about learning which string/fret combination sounds a given note, but instead, given a certain chord:
1. where is the root of that chord, and with that as my anchor...
2. where is the 3rd, 5th, and 7th of that chord? Only once I can easily find those three intervals...
3. where is the 9th, 11th, and 13th. Finally, the sharps/flats of all of the above.
When it comes to organizing all of this across the fretboard, I've found the heptatonic approach to the fretboard to make the most sense and the most economical. YMMV.