Which note is found on the 4th fret of the 5th string?

The note located on the 4th fret of the 5th string, which is the A string, is indeed C#. This can be determined by understanding the music theory related to the fretboard.

In standard tuning, the 5th string (A string) provides a starting point to identify notes based on the chromatic scale. Starting from the open A (0 fret), as you move up each fret, you encounter the following notes: A (open), A# (1st fret), B (2nd fret), C (3rd fret), and then C# on the 4th fret.

This progression follows the sequence of half steps on the fretboard, which means that each fret represents a half step increase in pitch. By counting up from the A string, it is clear that upon reaching the fourth fret, the note being played is C#. This understanding of the chromatic scale and the relationship between frets and notes is essential for mastering the fretboard.