I wish we could dispell the myth that stars and other cast members are frequently absent from matinees.
I've been attending plays and musicals since 1963 and most times I see matinees. For the most part the stars show up but there are times when they fall sick or have urgent family emergencies. However, unless otherwise advertised, the stars are contracted to give 8 performances a week
(During Pearl Bailey's run in Hello, Dolly!, the ads clearly stated: Thelma Carpenter will play Dolly at Wednesday and Saturday matinees)
On the other hand, one of the most wonderful experiences I've had in the theater was seeing Max Clayton go on as Harold Hill in the recent MUSIC MAN.
Dom't be afraid of understudies!
"Long live God!" (GODSPELL)