Electric guitars were guitars that used electric signals to create sound.
In 1959, a member of the Lorells used an electric guitar. The Seventh Doctor later played with it. (TV: Delta and the Bannermen)
When Rakweed was going to cover the Earth, Clyde Langer used Haresh Chandra's electric guitar to make the same sounds and vibrations as the school bell of the Park Vale Comprehensive School, which had destroyed the Rakweed before. The guitar sound broke the plants' communication methods and neutralised the Rakweed spores. This killed off the Rakweed and saved Luke Smith's life. (GAME: Sound) Later the electric guitar stood inside Clyde Langer's bedroom. (TV: The Curse of Clyde Langer)
The Twelfth Doctor showed himself to be an excellent guitar player and had his own electric guitar. (TV: The Magician's Apprentice, The Zygon Invasion, Hell Bent, The Pilot, Twice Upon a Time)
In 2050, Darius Pike played the electric guitar, but the guitar sound was stopped by an Aeolian. (TV: Aeolian)