The signs when they hear a song from their childhood-

Turns up the volume, sings along a little, texts their friends about it: Capricorn, Scorpio, Taurus

Records themselves singing along then posts on social media with the caption "remember this song?": Virgo, libra, Leo, Pisces

Completely freaks out because they are so excited, start hyperventilating as they have flashbacks, and by the time they calm down the song is over: Sagittarius, Cancer, Aries, Gemini, Aquarius