The ES-150 (pictured) was an electric guitar made with a "Spanish" neck. The ES stands for Electro-Spanish. 150 because it cost $150 (along with an EH-150 amplifier and a cable).
The most important player of the ES-150 was Charlie Christian. His flowing solos and warm sound revolutionized the jazz guitar influencing countless players there after..
Here's Charlie Christian live in small club. Even this 1940 's electric guitar solo has the first strains of 1950's rock and roll.
(There is no recorded film of Charlie Christian!)
