Click here to learn a little about how pitches in Upbeat Bird are selected. In short, the game uses an improvisation algorithm through limited random selections. The limits for the bass are determined using the notes that came before and after. The limitations for the bird sounds are generated using the direction of the bass line.
This perfect upbeat probably yielded a leap (pun intended).
What is most compelling about the music is that the bird sounds are completely based on user input. A sound occurs whenever the player taps to jump. Then the pitch is based on a combination of what the bass is about to do, and on when the player jumps. If the player succeeds in performing a perfect upbeat, the bird’s melodic line leaps. The line will also leap if it has to change direction due to range limitation. Otherwise the melodic motion goes only by step.
So then, rapid tapping will usually result in stepwise motion. Since rapid stepwise motion is more desirable to listen to than rapid leaps, the result is good melodic content during dense clusters of notes. Accurate upbeats, on the other hand, yield leaps. Since this requires slower rhythm, it makes sense that these notes would be where leaps occur. This keeps the line interesting during sparse passages of improvisation.
Small Steps Toward Good Improvisation
These rules have exciting possibilities both inside and outside of Upbeat Bird. It yields a form of guided improvisation. While eliminating pitch selection, it gives total control of rhythm to the player. This will lead to other games and tools to guide people efficiently towards logical improvisation.