It’s one of the greatest rock voices of all time: alternately melodic, raw, sweet and supercharged while also extremely versatile and infused with different characters. Paul McCartney’s lead, harmony and backing vocals have graced tender ballads, balls-to-the-walls rockers and almost everything else in between. But how did his talents in that regard develop and expand down the years? What has caused the vocal deterioration: insufficient technique, too much weed, old age or undisclosed health issues? And what, if anything, can be done about it?

The answers to the last two questions—provided in our interview with legendary voice teacher to the stars Seth Riggs and his wife/vocal technician Margareta—may surprise you. Heart lead guitarist Craig Bartock and acclaimed music critic/musicologist/author Allan Kozinn are our co-hosts.

For info on Seth and Margareta Riggs, go to theriggsvocalstudio.com