The standard accordion
Though hardly ever seen these days, the accordion was extraordinarily fashionable in Europe all through the nineteenth century, owing to it being invented in Germany. The instrument virtually all the time options two unbiased keyboards which are every held by a single hand, and they are often moved nearer or additional aside because of the bellows becoming a member of the edges. Pushing and pulling the accordion forces air by way of the instrument the place it could possibly then be modified by the keys, thus creating totally different notes.
Linus Åkesson was impressed by the accordion and its typically classic nature, so it was solely pure to mix it with one other piece of retro know-how, the Commodore 64. The ensuing venture, referred to as the Commodordion, swaps the normal piano-style keyboards for whole Commodore 64s whereas nonetheless having bellows between them.
Creating melodies and chords
A few of Åkesson’s earlier work has included his customized software program named Qwertuoso. It’s a small program made for the Commodore 64 that permits the keyboard to rework right into a synthesizer. Together with keys for taking part in notes, customers can press modifiers to pick numerous modes, modify the waveform, and carry out particular features. Åkesson loaded Qwertuoso onto the left C64 for normal enjoying.
Programming easy loops
In contrast to the left C64, the precise one is a bit particular in that it not solely helps enjoying chords through the a number of rows of alphabetical keys in dwell mode, however may retailer and play loops. To program a loop, the document secret is pressed, which transforms some keys into drums, bass, or particular chords. From right here, the participant inputs their sounds in rhythm with a background metronome and at last saves the consequence. Hitting both F1, F3, F5, or F7 throughout dwell mode will begin enjoying the saved loop.
Bellow design
As a result of lack of want for transferring air by way of a sequence of inside pipes, Åkesson had to determine a special method of turning the pressure from the transferring air within the bellows into modifications in sound. His preliminary strategy concerned attaching a temperature sensor to a heating factor and measuring how a lot the temperature modified in response to the movement of air round it. Sadly, this method turned out to reply far too slowly to modifications in airflow and was even probably harmful.
As a substitute, Åkesson realized a while later that blowing right into a microphone would produce very noticeable modifications in its outputted waveform, thus making him understand {that a} easy microphone subsequent to a gap within the in any other case hermetic bellows may measure these strain modifications. The bellows themselves have been long-established by taping collectively previous floppy discs (in fact) with gaffer tape.
Outputting audio
The audio coming from every Commodore 64 is combined equally inside a mixer and is shipped to a multiplying digital-to-analog converter (DAC). For the reason that bellows are supposed to manage the amount, the waveform from the microphone is first transformed right into a sequence of peak ranges because of an “envelope follower” program working on a microcontroller. This worth acts as a achieve on the C64 values with a view to enhance or lower their whole quantity.
Taking part in the Commodordion
As seen and heard in his demonstration video, Åkesson’ Commodordion is an amazingly succesful instrument that may output a variety of sounds with a enjoyable 8-bit twist. You possibly can watch his rendition of Scott Joplin’s well-known “Maple Leaf Rag” right here on YouTube.
