1. Unterlanders Heimweh 2. Greensleeves 3. Die Lorelei 4. Old Folks and Home
Spotted this for sale on eBay US. It was being sold together with a bundle of normal Casio keyboards. This appears to be a clone of RO-551, presumably bundled with some rebadged keyboard, although I can find no other information about the "Sonnet" brand.