[ Register or Signin to view external links. ]

This achievement is missable. It is earned over the course of a single playthrough, particularly in Mission 2, Edge of the World, Mission 6, The Dust District, and Mission 8, The Grand Palace.

The first opportunity you'll have to listen to the musical duo's song is during the second mission. Before reaching Addemire Station, just north of the Overseer Outpost, there is a small market-like area with several NPCs roaming around. The two musicians can be found - and heard - in this market. Stick around and listen to the song for a few minutes before carrying on with your objective(s).

Later, on the sixth mission, they can be found inside the saloon where Paolo is located. It may seem wise to eliminate the Vice Overseer and then enter the saloon - so that the Howlers will not attack you - but this will cause the musicians to disappear. Instead, head into the the saloon as soon as you're able to (remaining undetected, of course), and sit yourself in the hallway just before the parlor (or on the balcony of the upper floors). You can hear the song from afar so long as you're facing the musicians and/or using your spyglass. Again, listen to their song for a few minutes before continuing on with the mission.

The third and final opportunity comes during the eighth mission. Just before passing through the Wall of Light to the Grand Palace, hitch a right on the street and make your way over to the well-lit alleyway. There are two Howlers sitting down and speaking; wait until the enemies have finished talking and have separated before eliminating them. Now climb the stairs and in the distance you should be able to see the musical duo surrounded by three civilians. Join the crowd, listen to their song for a few minutes, and then be on your way. The achievement should unlock as you leave the alleyway.

NOTE: Do not cause any sort of panic in Mission 2, 6, or 8, otherwise the musicians will run away and you cannot hear their songs. Additionally, it is reported that if you rob multiple Black Market shops (more than one) during your playthrough, the third musical duo will never show up.