Musical Calculator refers to a series of videos and songs featuring a calculator being used a synthesizer keyboard piano.

The practice of using a calculator as a synthesizer has existed since before the internet. In 1978, the Casio electronics company released a calculator that could be re-programmed to play music and record to cassette tape.^[1] On May 10th, 1981, the German electronic music band Kraftwerk released the album Computer World. The album's second track, "Pocket Calculator," made use of the Casio FX-502P (song below).^[2][3]

While touring on the Computer World album, Kraftwerk manufactured customized Casio VL-80 calculators that contained sheet music to play their songs.^[4] Fans could then play songs from the record on the synthesizer calculator.

On April 27th, 2007, YouTuber^[8] matanica uploaded a video of the Casio mini keyboard calculator combo electronic piano. The video (shown below) received more than 21,000 views and is the earliest available example of the musical caluclator on the site.

Later that year, YouTuber^[9] ccruzado released a pair of videos. On June 17th, they posted a video of Tetris music being played on a Casio ML-81. The video (shown below, left) received more than 171,000 views in 10 years. Three months later, they uploaded a video of the theme to The Simpsons and received more than 28,000 views in 10 years.

On August 25th, YouTuber ^[5] It's a small world posted a video of a person playing the Justin Bieber song "Friends" on two calculators. Within three months, the video has been viewed more than 17,000 times.

Several days later, on September 1st, the account published a video of a person playing "Despacito" on two calculators. The post (shown below, left) received more than 3 million views and was featured on NPR^[6] and the Verge.^[7] That week, they published a video of the person playing "All Star" on a calculator, receiving more than 2.9 million views.