We all know that
In no order of importance...
1. A Xylophone.
Don't be bored to tears yet.... we all know they're great toys/instruments, especially for babies and toddlers. Simple and easy to play, these introduce music-making to the young and uninhibited!
2. Shakers (Maracas)
I especially like the fruit shakers. These great shakers are just a few examples.... maracas are great for any rhythm activity.
These were always the favorites in my classroom - why not give your child free reign on one at home? Within reason, of course.... You may run from the house screaming if you don't keep it hidden sometimes.
Another favorite with most kiddos is this one.... I suggest one with a head (skin cover) on it because kids tend to gravitate to that kind more, but more importantly, it allows use as a drum and a shaker too. Please try and keep your child from hitting their sibling on the head with it, though.
5. Pots, Pans, Spoons, Bowls, etc...
Nothing beats what you can find around the house to make into a drum of some sort. Lots of excellent musicians began experimenting rhythmically with these humble beginnings. :-)
Here are two combined kits I like as well where you get a bunch of instruments in one group:
B. Parum Pum Pum Drum:
Great for little ones - there are lots of sounds to explore with this set and they're designed so creatively. The container is a drum which even has a strap so your little darling can march around like the little drummer boy him(her)self!
Rhythm Band Rockin' Rhythm Bag:
This one is better for older kids.... beware of the rhythm sticks. I know what my boys would use those for right now and it would not be for music!
Reminder... As stated before, I vote for getting your child singing first and foremost. Rhythm instruments are also a natural outflow of your child's musical curiosity, so encourage them at age-appropriate levels and demonstrate well by using them correctly and keeping a beat. Don't just expect them to know what to do with these instruments, though - demonstrate for them with enthusiasm.
My suggestions for music to use these with? Any song you're singing with them... or turn on some salsa music and let 'em at it. :-)