My first MP3 player was an RCA Lyra.It was a small and robust handheld, with a rubbery red exterior, shaped to be held in one’s palm with ease. The buttons were rubbery too, in part because the player was splash-proof, as it was marketed to runners who presumably often got wet. My dad got it for me at RadioShack.My Lyra could do only one thing: play music. Actually, two things: play music and the radio. Putting the radio (an analog format) on a digital music player is a form of two design phenomena: functional adjacency and transitional convergence.An adjacent-function tool is a tool that absorbs a complementary or inverse action within the same use-case. For instance, the hammer drives and removes nails or the pencil writes and erases. The function of radio listening is adjacent (complementary and not inverse) to music listening, especially considering the radio was the main source of music at the time. It thus made sense for the designers to afford both on the device to meet users’ existing behaviors.This speaks directly to the second phenomenon: transitional convergence. Transitional convergence is the combination of old and new formats during a period of technological overlap. This design decision allows for the capture of a larger market by both serving early adopters and laggards who want to keep using the previous format. Think for instance of the VHS/DVD combo players that many had in the aughts.Functional adjacency and transitional convergence work well for hardware because the functions are contextually-related, they are part of the same task ecology (i.e. what the user is trying to do, the actions that precede and succeed the task, the nearby environment, expectations and adjacent behaviors).When objects are designed with functional adjacency in mind, their potential utility for consumers increases. For instance, having both a radio and a MP3 player presumably allows the runner to listen to their favorite songs and then catch up on the news as they recove