After completing Act 1 and passing Mission 11 "Playing for Time", you will have access to Cyberpunk 2077 The Ballad of Buck Ravers side job. To start it, go to Japantown, more exactly at the market next to Jig Jig Street. Then look for the street musician near the stairs.
Walkthrough of The Ballad of Buck Ravers
Johnny will appear and you will have an exchange with him about the performance of the guitarist. Johnny will then tell you some memories and in particular remember that there should be a recording (bootleg) of a concert that Samurai did in a nearby club, the Rainbow Cadenza Club.
A marker is placed on the map to lead you there. You then realize that the club has been bought and turned into a Japanese restaurant. Approach the counter to engage in dialogue with the cook. This will confirm that the club no longer exists, but that you will have more information from a market seller.
You will find it right next door. Start a conversation and then convince him with the help of Johnny that you are a true Samurai fan. He will offer you to recover the famous old recording.
The name of the mission is also the title of one of the pieces of Samurai in play integrated into the OST.
Original content by Irezumi.