Does anyone here have suggestions on what I might provide for a tuning/acoustics-obsessed toddler?
DS is 2.5 and probably on the autistic spectrum, though this is changing very rapidly at the moment, and manifests mostly as very strong interests. The most enduring of the interests (and a theme running through all topics) is sound, specifically stuff like harmonic series, acoustics, tuning systems. He has hyperacusis which is a nightmare a lot of the time in the real world, but a source of joy and wonder when he e.g. points out the 5ths on my violin are beating against the (increasingly out of tune) equal-temperament piano. Or stands in front of someone's empty concrete garage singing different notes to work out which resonates best. Or sings something difficult, in tune (he has been good with pitch for ages but only recently has started to have the vocal control to sing without it being frustrating).
He loves bells, but there's only one peal where we live and the people who infrequently ring those (probably quite rightly) aren't interested in giving tours. Likewise the only piano tuner in town, who kept asking if it was time for DS's nap when DS sat silently agog watching him tune our piano. DS talked about that to anyone who would listen for ages, and still mentions it nearly a year later.
We have a kiddy glockenspiel that DS plays but its tuning isn't great. He plays intervals on the piano and comments on the tuning. We play violin every day but he is 2.5, wilful, opinionated, awful at following directions, and more interested in tuning it than playing Twinkle variations, so definitely not ready for lessons (good Suzuki teacher here for later on though; and DS can sing all of Book 1 now so should take to it quickly if he ever does start lessons).
Can anyone recommend books, DVDs, instruments, anything?? Nice demonstrations of harmonic series or tuning, in particular?