Here's Ana playing a guitar that's as big as she was at the time. What Ana is saying at the beginning of the video is that it was her brother Viktor's guitar that she was playing, her parents couldn't afford a new guitar for her. Viktor is also a world famous classical guitarist.
You can listen to any of Bach/Beethoven/Mozart's symphony. They are amazing.
If I have to suggest a particular classical piece of music, it will be the Overture from Marriage of Figaro [composed by Mozart]. This is my favourite. Very rocking piece.
The depth of classical music is massive. The list of composers and the amount of classical music out there is non-exhaustive. Even following the works of a given composer is a massive task. The other day on radio, there was interview with someone who studied Beethoven's music for 30 years and finally published a book/biography!!!!
I listen to classical music [classic fm] on my way to and back from work. I drive an hour everyday [each way]. So, thats two hours of good, non-stop classical music. I have discovered a lot of composers like Brahms, Vivaldi, Strauss, Rachmaninov, Holst etc.. through the radio when commuting. It is very soothing!