Misc: Organic chemistry is the study of materials that must contain what?

Questions

- (1) Generally a free style keyboard piece; (2) An organ solo played before and after an Anglican service.?

(Ger.) - An appoggiatura.?

(Ger.) - A prelude.?

- A slow or fast dance in triple time with the characteristic one beat and one chord in the bar. The waltz became universally popular in the 19th century with Viennese composers.?

(Ger.) - Waltz.?