For a music appreciation component maybe consider listening to Classics for Kids podcasts. Each one is 6 minutes long and my kids and I have both developed such a love for classical music through them. We tend to listen to one each morning as we eat breakfast.

I have a rising 5th grader who I've homeschooled since 2nd grade using MEP. She is very strong in the conceptual understanding of math (math thinking, as I call it). She is decent at calculating too. I am looking ahead to her transition from arithmetic to Algebra and beyond. I've always imagined that after MEP Y6 she'd transition into AoPS so I would have more support in teaching her and she could have an increased independence, although I am a mathy person so she won't be fully self-taught. But today as I looked at AoPS sequence I realized that they actually offer 7 years of math and if she starts Pre-Algebra in 7th grade after MEP Y6, then she's only got 6 years and would not be able to complete a high school level Calculus course if she desires. I hate feeling like I'm already making that choice for her in these late elementary years by default because of when I have her cut over to AoPS. If you have been a MEP family and completed MEP Y5 and/or Y6 and then transitioned into AoPS can you give me some input on what you think is the best transition plan?

I used The Elements as our Grammar stage Chemistry spine this year, but ended up feeling like it left out a lot of important Chemistry concepts so I supplemented. I actually pulled some ideas from this free resource: http://www.middleschoolchemistry.com I think you could complete The Elements, then cover any topics in Middle School Chem that weren't already covered in The Elements, then do organic chemistry through her Carbon Chemistry book. Also, we like documentaries or movies that correspond with what we are learning. We enjoyed the PBS series "Mystery of Matter."