I’ve dreamed of a device similar to this since I was child. It would be thrilling to isolate different stems from classical or really synthy music. The device looks like it’s a brookstone product from the 2000s though…
Stemroller (currently also on the front page) will do just that! (Well the isolation part. Putting them back together enjoyably is left as an exercise to the reader. https://news.ycombinator.com/item?id=32359325