This achievement occurs during Episode 2 - Get Tannen
Once inside Tannen's Speakeasy Cueball will be playing the piano for Trixie who is on stage singing, next to Cueball is a collection of sheet music, there are 5 songs to hear Trixie sing to, interact with the Sheet Music to select the songs, let them fully play out before selecting the next.
The songs are:
''I Don't Care''
"Angry Song"
"Sad Song"
"Secret Song"
"Happy Song''
Credit to T_l_M_B_0 of PST