Music connectivity is an amazing thing. By now, we're all used to the instant connectivity that puts the world at our fingertips. From desktops or devices, we can purchase, post, pin, and pick anything anywhere. We are connected to the world and each other like never before. But how does it happen? How does data get from here to there? How do different devices and applications connect with each other to allow us to place an order, make a reservation, or book a flight with just a few taps of things? The unsung hero of our connected world is the application programming interface or API. It's the engine under the hood and behind the scenes that we take for granted, but it's what makes possible all the interactivity we've come to expect and rely upon. But exactly what is an API? It's a question everyone asks. Okay, not really, but we're glad you did. The textbook definition goes something like this: In computer programming, an application programming interface (API) is a set of routines and protocols. Okay, to speak plainly, an API is the messenger that takes requests and tells a system what you want to do and then returns the response back to you. To give you a familiar example, think of an API as a waiter in a restaurant. Imagine you're sitting at the table with a menu of choices to order from. In the kitchen is the part of the system which will prepare your order. What's missing is the critical link to communicate your order to the kitchen and deliver your food back to your table. That's where the waiter or API comes in. The waiter is the messenger that takes your request or order and tells the system, in this case, the kitchen, what to...