John Tullman: Letective Adventures!

You decide to inspect the rack lined up with instruments.
The rack is holding harmonicas. A lot of them. You count forty in total, ranging from mini harmonicas to bass harmonicas. Some of the harmonicas are made out of cheap plastic, while others are plated with gold and diamonds. Looking at them, you can't help but feel shocked at the sheer amount of number and variety.
Harmon notices your shock.
"Uh, sorry about that...." he says chuckling. "I just love collecting harmonicas of every kind. I can't help myself! I will tell you that my precious harmonica is not stored here though. It was in the safe next to this rack."
You quickly write down:
"Instrument rack: filled with forty harmonicas of all varieties. Ranges from cheap plastic mini harmonica to gold and diamond plated bass harmonica."
What do you inspect next?