Misc: When was apartheid introduced in south africa?

Questions

In 1970, 100 cellists played Sardana in tribute to what composer ?

Who wrote the Skater's Waltz ?

Domenico Scarlatti's works are often identified with "L" and a number. Whatdoes "L" stand for ?

Who wrote most of Mozart's Symphony No. 37, K. 444 ?

Although Mussorgsky wrote Pictures at an Exhibition, whose orchestration of it is usually heard ?