A concert with music inspired by the movie “Good Morning Vietnam” will headline the first-ever Veterans Appreciation Day on Friday, the opening day of the Three County Fair in Northampton.

Appearing on the fair’s Farm Museum Stage, the oldies band Decades will play music of the late ’60s from the soundtrack of the Robin Williams film from 7 to10 p.m., with assistance from Bob Flaherty of WHMP’s “The Morning Show.” A Vietnam veterans recognition ceremony will take place during the concert.

“Veterans Appreciation Day is a way to say thank you to veterans,” says John Paradis of VA New England Healthcare System. “Veterans receive free admission to the fair on Friday and can talk with local, state and federal veteran representatives while they’re there.”