Puzzle - Tuning Forks

On 5/30, Volo's Twitter account posted the following text and image..."I have received a key from Elminster! The accompanying message imparts that he knows not now who he can trust, and therefore sent this clue to me direct. It says: 'As it began, this quest will end with keys. Material concerns revealed by scientific means.' #NoStoneUnturned - @Glovers_Travels, 5/30 @ 12:23PM" He added a subsequent clue... "Could this have anything to do with the Instagram puzzles? That seems to have been the case for the spell components with a high degree of frequency. - @Glovers_Travels, 5/30 @ 4:27PM"...which seemed to suggest that the Instagram pics might be a factor, but the clue seems to be more for emphasizing FREQUENCY.

Solution
The first step is to find the appropriate frequency for the given note using "scientific pitch", which is based on "Middle C" being 256 Hz: Now, for each tuning fork, divide the frequency by the value below it: Then you must convert the waveform images into numbers from top to bottom:"02""30""13""24""122""12"Volo's next hint pointed the way:"Tread carefully with this one. I've been working on it while I'm en route to Uganda, and it's really easy to get off-base... # NoStoneUnturned - @Glovers_Travels, 5/30 @ 7:13PM"Base being the keyword, the numbers from the waveform images were in the numeric base calculated by the frequency division above. So the values needed to be converted to traditional Base-10:
 * Middle C: 256 Hz
 * D: 288 Hz
 * E: 320 Hz
 * F: 341.3 Hz
 * G: 384 Hz
 * A: 426.6 Hz
 * B: 480 Hz
 * 256 (C) / 32 = 8
 * 288 (D) / 48 = 6
 * 384 (G) / 32 = 12
 * 320 (E) / 64 = 5
 * 480 (B) / 120 = 4
 * 384 (G) / 128 = 3

Converting the numbers to letters, we get the word "BRONZE", the material component of our spell being a BRONZE TUNING FORK.