[okiejonwilliams]

In-ear binaural microphones can be used to reproduce in with headphones what a listener hears during a live performance.

[jackcarter]

How expensive would that be? Plenty of people already wear headphones to shows. I bet some of them would love to have a high-quality audio souvenir, replicating exactly what they heard.

[okiejonwilliams]

One example is the Roland CS-10EM microphones/earphones. A pair is $99 on Amazon.