Jem Aswad Senior Music EditorLike many people, John Sebastian, a Rock & Roll Hall of Fame inductee for his years as a founding member and vocalist for The Lovin’ Spoonful, was getting ready to write off 2020 as a wash.After abruptly canceling a planned solo tour in March due to the pandemic, “I was looking down the barrel of no work — ever,” Sebastian says on the phone from his home in upstate New York.