[Pentegarn]

I would think Simon and Garfunklel would be a good choice for similar reasons I would choose Yes. Vocally Simon and Garfunkel are very pleasant, just like Yes is instrumentally pleasant. I would go with complex pieces that are good examples of their genre. Xanadu by Rush would be a good synthesized rock piece, YYZ by Rush would be a good complex guitar piece (though the baby might react poorly to electric guitars, they might sound scary to them)