Thomas Edison used wax for the first commercial phonograph cylinders.
Edison’s original 1877 phonograph recorded sound on a sheet of tinfoil wrapped around a cylinder. Tinfoil recordings were fragile and could usually be played only a limited number of times. Later development of wax recording surfaces made cylinders more durable and practical for commercial use.
Wax cylinders could be shaved or polished and recorded again, which helped reduce manufacturing costs during the early recording industry. Their surface also supported clearer grooves than the original tinfoil format. Commercial cylinder records became an important way for people to buy and hear recorded performances.
Tin and tinfoil are associated with Edison’s first phonograph demonstration, so they are common answers to a different question. Wax is the key material for the improved commercial cylinder format, not the earliest experimental recording surface.