Abstract: I welcome you to the fourth issue of the IEEE Communications Surveys and Tutorials in 2021. This issue includes 23 papers covering different aspects of communication networks. In particular, ...

While I was playing “Carol of the Bells” in public, a 9-year-old girl joined in with her violin and together we created a spontaneous duet that caught everyone’s attention. Her timing, tone, and ...

I was playing piano in a public space when a violinist appeared and started playing along. We didn’t plan anything — but our instruments seemed to connect instantly. Her tone, timing, and emotion ...