What word or phrase describes this musical instrument?

The answer to the OP's question is definitely "Barrel Organ" but there is a degree of confusion about what this term means and also around the terms Barrel Organ and Hurdy-Gurdy. In particular there is a comment discussion going on between @DarrelHoffman and @Édouard. I was going to add my own comment when I found this site belonging to a maker of barrel organs from which I copied the following paragraph:

To clear up some common misconceptions, these pages are devoted to 'organs' - that is, instruments with pipes that sound when air is blown through them, just like a church organ, but a lot smaller! 'Barrel Organs' were a common sight years ago, and some did contain air-blown pipes, but the majority of these were actually very large versions of a musical box - as revealed by the 'metallic' sounds that they produced. Another name sometimes wrongly applied to Busker organs is 'Hurdy Gurdy'. This is actually a mechanical violin, where a rotating wheel takes the place of a bow, and notes can be sounded by operating keys to press the violin strings onto the wheel.

This said so much that I wanted to say and with so much authority that I thought I should share it with the community. The only thing I would add is that true hurdy-gurdies are instruments which need proper musical skills to play whereas barrel organs of all types are hand-cranked mechanical instruments where the tune is determined by spikes on a rotating drum or holes in cards or paper. For those who are interested I would suggest that they enter "hurdy-gurdy" into a search engine. There is a wealth of information and demonstrations out there.