Hi @nebukadnezar thanks for the question, you’re right we don’t list minimum specs for balenaSound, I’ve spotted in this old post a Zero W with 512mb of ram is adequate and personally I use a Pi3 with 1mb no problem.
The comment in the older post still stands though that getting a Pi with a higher spec will futureproof any additional things you may want it to do for your Father in the future, but wouldn’t be neccessary for balenaSound alone.