As much as it’s delightful to hear and see extraordinarily talented musicians perform a concert, it’s a special treat to watch them in rehearsal. Today’s Beautiful Music features the magical interplay of violinist Augustin Hadelich and bassist Xavier Foley, with pianist Chelsea de Souza. They were rehearsing the Grand Duo Concertant by Giovanni Bottesini for the La Jolla SummerFest 2021.