Last year, Google released a 90-second piano melody created by Magenta, an open-source project that uses the TensorFlow AI engine to try and produce art and music. Now, members of the public can test the technology with an intelligent, piano-playing web app called A.I Duet.

Once you load up the web page, just hit a few notes using your keyboard or mouse and the artificial intelligence will respond with a tune that (usually) compliments what's just been played. Sometimes the AI will start playing even before you've finished your piece, leading to some impressive human/machine jamming sessions.

The quality of the resulting duet can vary, but most of the time it's pretty amazing. How good it sounds can often depend on your skills with a piano - my efforts weren't exactly on par with Elton John and Billy Joel.

The program uses neural networks trained with a machine learning system that has been fed a huge number of example melodies. The AI remembers the connections between the notes' timings, sequences, etc. so that when you play something, the 'tune' is compared to what it's learned. A.I Duet then respond with the best match, all in real time.

Musician and coder Yotam Mann created the program along with Magenta and the Creative Labs team. "Making music using code isn't a new thing at all, but machine learning gives us a different way to go about it," he said. "If I was trying to make AI Duet with more traditional programming, I'd have to write out lots of rules."

The experiment is yet another example of how quickly AI is advancing. It's already beaten the world's best Go and Poker players and created a short movie. Could the next step by co-writing a hit song?