Learn the גמרא דף נ: “אמר רב יוסף מנא אמינא until “ואיבעית אימא” (fourteen lines from bottom of the Amud)
Review תוס’ דף נ. “שאינו
Tosfos asked – We have a rule אין שבות במקדש and playing musical instruments are only prohibited from a gezira drabanan so why did the rabanan not allow the playing of the instruments for the שמחת בית השואבה on Shabbos or Yom Tov? Tosfos answered because the music played was just because of שמחה יתירה.
Review תוס’ “דף נ: “ורבנן
How does that conform with the reason that Tosfos “דף נ: “ורבנן gives that there were many musical instruments and they were prone to breaking that needed to be constantly fixed?
When do we apply the rule of אין שבות במקדש?
Learn רמב״ם הלכות קרבן פסח פרק א הלכה טז
And רמב״ם הלכות תמידין ומוספין פרק ה הלכה י
And צל”ח פסחים ס”ה
https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=104