This Panasonic .1uF capacitor is often used in electric guitar tone controls because it offers a good balance of high-frequency roll-off, resulting in a "warmer" tone, especially when paired with single-coil pickups. 

 Here's a more detailed explanation: 

• High-Frequency Roll-off:

A .1uF capacitor is a common value that effectively filters out a significant portion of the high frequencies, creating a smoother, less bright sound.

• "Warm" Tone:

This type of capacitor is often considered to produce a "warmer" or "rounder" tone, as the high frequencies are reduced, which can be particularly desirable for single-coil pickups, which can sometimes sound too bright.

• Leo Fender's Choice:

Leo Fender originally chose a .1uf cap for his single-coil guitars, and early Broadcasters, no-casters, and Telecasters had a .1uf cap that was fully engaged in the circuit when you selected the 3rd position on the selector switch.

• Complementary to Single-Coil Pickups:

The characteristic high-frequency roll-off of a 0.1uF capacitor can be a nice complement to the typical sound of single-coil pickups, which can be prone to a brighter, more "tinny" sound