Dr. Johnson was the first person to perform spectrum analyses on cymbals.

These analyses showed the frequency peaks that give each cymbal its unique sound, and which allow cymbal-makers (cymbal-smiths) to adjust their timbre by changing the heating, hammering, and lathing procedures to produce the desired spectrum.

He can perform spectrum analyses on all types of percussion instruments, including drums, which can result in an easier path to improve the sound.

John has been a jazz drummer for more than 50 years and is an expert on the sound and design of each percussion component in a drum kit, including snare, toms, bass drum, and cymbals.