While listening to shortwave radio , Pena heard a broadcast of throat singing , the Tuvan art of manipulating overtones while singing to make higher frequencies more distinguishable , essentially making it possible to sing two notes at once .
SCONJ VERB PART VERB NOUN , PROPN VERB DET NOUN ADP NOUN NOUN , DET PROPN NOUN ADP VERB NOUN SCONJ VERB PART VERB ADJ NOUN ADV ADJ , ADV VERB PRON ADJ PART VERB NUM NOUN ADP ADV .