First Time Sing-Along Share definition Flag The act, usually performed by an elderly person, of singing along to a song despite having only heard it for the first time as it plays. Grandma: "hmmmm mmm mmmmm..."Bystander: "Sounds like a first time sing-along to me." First Time Sing-Along by wardy99 September 1, 2011 Get the First Time Sing-Along mug.