If you are not fortunate enough to attend an opera or ballet performance at La Scala, you must at least take a glimpse of the theatre - this is possible as part of the museum admission - 5 Euros for adults/4 Euros for seniors.
La Scala museum is open most every day, but closes for an hour at 12:30PM - Make sure you allow yourself enough time so that you won't be escorted out too soon. We did not see any guided tours or guides when we were there - arrangements I'm sure can be made. It was easy enough to read(in a few languages) about composers, musicians, performers, instruments or painting displayed in each room.
At one point during your visit, a guard will open a "viewing box" for you to see the theatre- an orchestra was practicing during our visit. You only spend a couple of minutes there and cannot use cameras, but it is magnificent.....the immenseness alone is breathaking.....a hugh chandelier.....the many, many, many opera boxes - gold with red velvet curtains - row upon row- upon row....Probably 9 tiers of boxes surround the entire theatre, yet you feel so close to the stage. What a privilege it must be to attend a performance.
We spent time enjoying busts of composers and performers, musical instruments of the 1800's and miniature porcelain figurines of musical significance. I especially was interested in the paintings of La Scala - "In the rays of the sun" - "In the mist of New Year's Eve" and the rendering of the original La Scala Theatre - you can feel the elegance and the "party atmosphere" of the time.
But....best of all....was the 2nd floor - Probably four rooms of manequins in costume!!! Such magnificent costumes, masks and headdresses - beads and sequins....So elegant and must be so heavy!!! These are not even protected behind glass walls - you could possibly touch them, but there were guards around to discourage this.
Unfortunately, we had only 45 minutes to enjoy the museum because of the midday break at 12:30PM - Plan accordingly if you like more time in a museum....We could have used our ticket all day but were on to other activities in the afternoon.