@raindrop prelude
Do you mean, music from the classical period with more predictable harmonic structures like Mozart and Hadyn? Or Classical as spanning from baroque to early 20th century music?

Hey guys, first of all, let me say, I am soooo glad to be back to the forum after 1 whole week of business travel. It's a challenge for an adult to continue piano practice let alone try to get good at sight reading etc. But I can assure you that we all get better. When I got back to piano after 20 plus years of absense, I had never heard of sight reading. Start playing a music that I have never seen before at tempo with all the expressions? I thought it was like a circus. I bought and tried sight reading Level 5 and found myself not able to do it. I could read slowly measure by measure but not the entire page or even 4 bars. Today I was trying to find a good music book for my friend (about 45) who just started piano again. I wanted to find a collection of short pieces that adult bignners can enjoy. So I picked up Schumann Kinderszenen Opus 15 and started playing them. I read the key signature first, tempo, meter, rythmic patterns, moved the fingers a little on the keys without the sounds, counted the beats and went with it. To my surprise, I now can sight read most of those pieces. Well, much slower than it should be perhaps, but with dinamics and expressions as required. It's been 5 years off and on since I resumed piano. I played a lot of different music in addtion to the pieces assigned to me by my teacher, including Christmas music and New Orleaans Jazz type stuff. So it is possible to learn to sight read as an adult as long as the pieces are a bit easier than the ones you are studying. I had childhood training about 7 years but never practiced sight reading as a child.