'Gran Vals' by Francisco Tarrega*. Ring any bells? Listen to it hear.
Nokia actually took 13 notes from the middle of it for their default ringtone. If only Francisco would have known what he started. Still he knew how to combine a beard, squint and footstool to maximum effect. That you have to respect.
*Tarrega was a 19th-century Spanish musician considered by aficionados to be the father of the modern classical guitar.