Paul McCartney and The Weeknd are among the artists who have donated a collection of signed or unique microphones for an upcoming charity sale.Reverb, the largest online marketplace dedicated to musical instruments, is hosting a charity auction next month to raise money for youth music education programs that have been impacted by the coronavirus pandemic.Other artists who have donated to the auction include: Billie Eilish, Bruno Mars, Alanis Morissette, Kesha, Damon Albarn, John Legend, J