The truth is, you don’t need to buy any instruments for your baby. You can make shakers by putting some dried beans or uncooked rice in a plastic container with a securely closed lid (watch out for those choking hazards). You can let your baby drum on pots and pans with a wooden or plastic spoon. You can clap and play patty cake with your baby.
However, if you want to buy actual instruments for your baby, here’s what I recommend (I do not receive any money from nor have any affiliation with these brands or companies–it’s just what I use):
I also like any of the Remo Kids line of instruments.
Here are pictures of the instruments my kid uses:
The Remo Kids Gathering Drum (left) and the baby instruments (right) are what my kid plays with. He likes to climb on this drum, and Remo instruments are durable enough to take it! This drum has a nice full sound and he enjoys exploring sounds on it. But these can get a bit expensive. The baby instrument set I bought back when I was working in pediatric hospitals. They’ve stood up well to lots of use and abuse and both they and the drum disinfect easily with clorox wipes or even the wexide hospital grade disinfectant. My kid teethes on those little drum sticks and they are pretty durable too. I don’t think they make these exactly any more, but the links above will get you pretty similar instruments.
And since research shows that moving together rhythmically can help develop social skills, take those home-made or store-bought instruments, (or even body percussion!) and sing and move with your child! Try this:
Hand your child an instrument and play a steady beat on a drum (or clap, or use shakers, whatever you have) and watch how he responds. Keep your beat steady and begin singing “Old MacDonald”. Match the beat you are playing as you sing, and rather than using this song to focus on animal sounds, for this activity, just use it to focus on the rhythm. See how your child plays with you and begins to move rhythmically.
Have a child with a developmental disability? You can do this too, but use a hand over hand technique to help your child play a drum or shaker rhythmically while you sing.