Joshua Bassett is getting into the festive mood.Bassett, along with his talented co-stars from the Disney+ series, rings in the holiday season with a 45-minute special, High School Musical: The Musical: The Holiday Special, on Friday, where they share their favorite holiday traditions, sing iconic favorites and offer two sneak peeks of the upcoming second season. ET debuts a first look at Bassett's performance of his original Christmas song, «The Perfect Gift,» which will be featured in season