Great advice from others here! Music is a huge part of our family. My dh plays piano and has always let our kids plunk along with him (even as babies). We love to sing and dance when dh plays. Recently, my kids started a "band": dh on piano, ds6 on electric keyboard, dd2 on xylophone or interpretive dance, me on vocals. Yeah, we probably drive our neighbors insane (since it's been window-open weather) .
When your dd is a little older, watch Disney's Little Einsteins. My ds cracks ne up when he starts discussing Beethoven's 5th, Mozart's Requiem and the like. It really helps make classical music accessible to kids.