My youngest is doing both Piano and Violin. Both Suzuki Method. He started piano at 2.9years old and violin at 3yrs 2mths. I find the approach very suitable for the very young. WE already have a piano in the house, altho’ we did buy those tiny violins for him. We started with the 1/32. I’d probably have him learn at least one more string instrument - maybe next year, but that’s because we already have this instrument in the house.