The primacy of the composer's written score has also led, today, to a relatively minor role played by improvisation in classical music, in sharp contrast to the practice of musicians who lived during the baroque, classical and romantic era. Improvisation in classical music performance was common during both the Baroque and early romantic eras, yet lessened strongly during the second half of the 19th and in the 20th centuries. During the classical era, Mozart and Beethoven often improvised the cadenzas to their piano concertos (and thereby encouraged others to do so), but they also provided written cadenzas for use by other soloists. In opera, the practice of singing strictly by the score, i.e. come scritto, was famously propagated by soprano Maria Callas, who called this practice 'straitjacketing' and implied that it allows the intention of the composer to be understood better, especially during studying the music for the first time.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What part did Mozart and Beethoven often improvise?
Ah, so.. the cadenzas to their piano concertos

The earliest clear evidence of hair or fur is in fossils of Castorocauda, from 164 million years ago in the Middle Jurassic. In the 1950s, it was suggested that the foramina (passages) in the maxillae and premaxillae (bones in the front of the upper jaw) of cynodonts were channels which supplied blood vessels and nerves to vibrissae (whiskers) and so were evidence of hair or fur; it was soon pointed out, however, that foramina do not necessarily show that an animal had vibrissae, as the modern lizard Tupinambis has foramina that are almost identical to those found in the nonmammalian cynodont Thrinaxodon. Popular sources, nevertheless, continue to attribute whiskers to Thrinaxodon.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): At what time is it believed the earliest known foramina existed?
Ah, so.. unanswerable

In 2014 artist Jack White sold 40,000 copies of his second solo release, Lazaretto, on vinyl. The sales of the record beat the largest sales in one week on vinyl since 1991. The sales record was previously held by Pearl Jam's, Vitalogy, which sold 34,000 copies in one week in 1994. In 2014, the sale of vinyl records was the only physical music medium with increasing sales with relation to the previous year. Sales of other mediums including individual digital tracks, digital albums and compact discs have fallen, the latter having the greatest drop-in-sales rate.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What medium has seen the biggest fall in sales as of late?
Ah, so..
compact discs