Wikiで学ぶ英語 - Jazz【Getz/Gilberto - Stan Getz and João Gilberto (1964)】

artwork : 本・アルバムなどの挿絵、イラスト

The artwork was done by artist Olga Albizu.
commence : begin, start

The recording sessions commenced on March 18, 1963, at A&R Recording Studios in New York and were completed on the following day.
restraint : 拘束、抑制、the ability to control or moderate one's impulses, passions, etc

Stylistic features of bossa nova such as restraint and lyrical objectivity are further developed in Getz/Gilberto building on Gilberto's previous albums.
shelve : 棚上げする、延期する、To put aside as though on a shelf

Producer Taylor shelved the project for nearly a year, because he was afraid the record might be a commercial failure. As a consequence, Getz/Gilberto was finally released in March 1964.
polished : 磨き上げた、洗練された、Refined or sophisticated

Besides playing piano, Jobim was also responsible for some of the arrangements and co-wrote nearly all of the songs except "Doralice" and "Pra Machucar Meu Coração", both old sambas, which are more polished and serious in Gilberto's version.

English Guy