I was fortunate enough to win a class set of Makey Makey's last year, which was great because my wife teaches elementary school science. COVID-19 put paid to using them in class, but we explored how to use them and had fun with the various piano applications out there, including trying out the classic banana piano. We decided to extend that idea slightly by using different fruit & vegetables, where the A, B, C, D, E, F, G keys were represented by a fruit or vegetable starting with the same letter. Easy & fun & sneakily educational!

Supplies

Makey Makey
Fruit and vegetables from A to G
Computer

Step 1: Choices

You have lots of options for which fruit & vegetables to use for each key. Here are some ideas, I'm sure there are many other choices we didn't think of. Bolded ones are the ones we tried.

A: Apple, Apricot, Asparagus, Avocado
B: Banana, Blueberry, Blackberry, Bean, Beetroot, Broccoli, Brussel sprout
C: Cherry, Cantaloupe, Coconut, Cranberry, Cabbage, Carrot, Capsicum, Cauliflower, Celery, Corn, Cucumber
D: Date, Durian, Dragonfruit
E: Elderberry, Eggplant
F: Fig, Feijoa, Fennel
G: Grape, Grapefruit, Garlic

We found that fruit with a waxy coat were not conductive enough (notably the apple), or those with a dry coat (unpeeled garlic). Picking fruit & veggies of similar size probably makes sense (but who doesn't want a dragonfruit key?).

Step 2: Connection Tips

You can alligator clip directly to the fruit or vegetable in most cases, but to make the connections clean and simple and avoid any mushing, we used pins and clipped to those (image 1). When playing a piano, it is good to have both hands free, so we clipped the earth line to a metal bracelet (image 2). Improvising one from a piece of copper wire also worked really well (image 3).

Step 3: Connect Makey Makey

Attach alligator clips to the arrow keys, space bar and earth. To access the letters w, a, s, and d, you will have to go to the back of the Makey Makey and plug wires into the labelled ports, and clip to those. If w, a, s and d are mysteriously not working, check you don't have caps lock on!

Step 4: Piano App

The first piano app we tried was the simple https://apps.makeymakey.com/piano/, which features just 5 notes. The notes are C (LEFT), D (UP), E (RIGHT), F (DOWN), G (SPACE). The 5 notes limit somewhat the possible tunes that can be played (see video for an example).

The Scratch piano at https://scratch.mit.edu/projects/2543877/ is very similar, but adds an extra note. The notes are C (UP), D (RIGHT), E (DOWN), F (LEFT), G (SPACE), A (CLICK)

Step 5: MK-1 Sampling App

This app was the best-suited one for this piano, as it allowed a full octave (ABCDEFGA), and has different sound options available. You can also change the key signature. You can play lots of tunes on it (video is "What should we do with a drunken sailor?").

Keys: A (LEFT), B (UP), C (DOWN), D (RIGHT), E (SPACE), F (W), G (A), A (S)

Step 6: Piano Genie

The http://piano-genie.glitch.me/ piano app looks neat, creating a visual cascade of notes as "an intelligent controller maps 8-button input to a full 88-key piano in real time". However, those inputs don't correspond directly to the notes, so the point of using particular fruits & vegetables is rather lost. Fun for those who can't play the piano, though!

We didn't try it at the time we had it set-up, but the Sampler App also looks like fun (thanks to MakeyMakey for the suggestion).