We're in an age where virtually any functionality can be added via a software patch, but back in the day when a synth's functionality was determined by its physical circuitry it wasn't particularly uncommon for analog synths like the polybrute to not have transpose controls. The closest they had was a tuning control, usually only there because the circuits would drift off tune, or to tune it to the key of an acoustic instrument or tape which wasn't at A=440Hz. If you wanted to play a song in a different key, you learned to play in the different key, or you relied on the tuning control which offered maybe ±2 semi-tones. That only really changed with the arrival of digital synths in the late 1980s.
