[FwL]

You'll be in the ballpark in both cases.

1. Depending on the scale pattern you learn and how you learn to play the pattern, the first note isn't necessarily the root. Whichever note in the pattern is the root will determine the key of the scale as you move that pattern around to different locations on the fingerboard.

2. If the melody sticks to the key signature, you should be able to work it out in whatever pattern you know. Ideally, you would also know at least one pattern for the other commonly used scales. Better still is to use your ear to figure out where the notes are and then figure out which scale those notes fit.

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