I'm the auxiliary percussionist in my school's jazz band, and normally there's a part for me, or I double a melody on the vibraphone, if there isn't. Right now, we're doing the song "Take the A Train", arranged by Sammy Nestico. There's no written auxiliary percussion part, and I'm not sure what part(s) to play on the vibraphone (I don't think it fits the theme either). I couldn't find any other auxiliary parts in other arrangements or performances either.
My band director told me to just make something up. What should I play for this song?