The are in the book songs without text. Check out samples from book: http: //osos.sweb.cz/preview-ukulele.pdf I devote to known technique: Double stop. The technique consists in the fact that two strings sound at the same time. The melody sounds on one string and the tone on another one where complements harmony. Ecah melody is arranged twice, once is up and for the second time down. One more addition to interpretation. I recommend to add tremolo or some nice "lick". on long notes according to your mood. Have a nice moment with mandolin.