Okay, Quetscher, I’ve had a chance to experiment with your technique and am happy to report that it works for me. It does make bending easier. So here’s my analysis of what’s happening. I think it has to do with what Jazzman1945 refers to as “the principle of the lever.” Basically, the key is a lever. A lever is often described as having three parts, right? The Fulcrum, the Force applied at one end, and Resistance at the other end. Our finger is at the force end of the melodica key, and the other end opens the the air vent to the reed. One way to make bending easier would be to design the melodica in such a way as to increase resistance at the air vent end. Another way, suggested by Kevin, is to create resistance at the force end by placing our thumb under that end of the key (or, as I suggested, creating friction with our thumb on the front end surface). Another melodica design approach would be to have longer keys. The key is about 3″ long; if that were increased to 6″, the lever would be twice as long, and we’d have more control. There would be trade-offs to a design approach. Your technique, though, adds the length of our finger to the lever, with force now being applied at the wrist joint, adding 6″ or so to the lever and thereby significantly increasing control over the size of the vent opening. Having our other fingers and thumb resting on the keyboard anchors the wrist and stabilizes the finger or thumb with which force is applied. Does this all sound right?