The viol (also known as the viola da gamba) is any one of a family of bowed, fretted and stringed musical instruments developed in the mid-late 15th century and used primarily in the Renaissance and Baroque periods. The viol family is related to and descends primarily from the Renaissance vihuela, a plucked instrument that preceded the guitar. Viols are different in several respects from instruments of the violin family.

Vihuelists began playing their flat-edged instruments with a bow in the second half of the 15th century. Within two or three decades, this led to the evolution of an entirely new and dedicated bowed string instrument that retained many of the features of the original plucked vihuela: a flat back, sharp waist-cuts, frets, thin ribs (initially), and an identical tuning—hence its original name, vihuela de arco; arco is Spanish for "bow".

An influence in the playing posture has been credited to the example of Moorish rabab players.

Viols most commonly had six strings, although many 16th-century instruments had five or even four strings. Viols were (and are) strung with gut strings of lower tension than on the members of the violin family, let alone the steel strings mostly used there today. Gut strings produce a sonority far different from steel, the former generally described as softer and sweeter. Around 1660, gut or silk core strings overspun with copper wire first became available; these were then used for the lowest-pitched bass strings on viols, and on many other string instruments as well.

Pierre Chevalier (1905 – 2001) was a well-known caver and mountaineer from France, with many alpine ascents and cave explorations to his credit. Chevalier is principally known for the exploration of the Dent de Crolles cave system over a twelve-year period (1936 – 1947), which became the deepest cave in the world. Chevalier recorded this exploration in his book Escalades souterraines (Subterranean Climbers).

Chevalier first visited the Trou du Glaz entrance in 1935, and was struck by the possibility of exploring beyond what was at the time considered technically possible. With Fernand Petzl, Charles Petit-Didier and others, Chevalier completed explorations that connected four entrances (Trou du Glaz, Guiers Mort, P40 and Grotte Annette) and established the Dent de Crolles as the deepest cave system in the world (-658m).

Much of this exploration was during the German occupation of France during the Second World War and at a time when both transportation and supplies were difficult to obtain. In addition, much of the exploration was undertaken from the bottom upwards. The exploration of Dent de Crolles demonstrated outstanding commitment and perseverance in the face of physical, technological and political adversity.

William Byrd (1540 or late 1539 – 4 July 1623) was an English composer of the Renaissance. He wrote in many of the forms current in England at the time, including various types of sacred and secular polyphony, keyboard (the so-called Virginalist school) and consort music.

Knowledge of Byrd's biography expanded in the late 20th century, thanks largely to the research of John Harley (Harley, 1997). Following the discovery of a document dated 2 October 1598 in which Byrd's age is given as "58 years or there abouts," it now appears that he was born in 1540. The older dating 1542–3 is derived from Byrd's will (endorsed on 22 November 1622) which describes him as 'in the 80th year of my age'. It now becomes clear that it must have been drafted about three years earlier than the date of endorsement. Byrd was born in London, the son of a Thomas Byrd (not Thomas Byrd of the Chapel Royal) about whom little is known. Byrd had two brothers, Symon'd and John, and four sisters. It is clear from a reference in the prefatory material in the Tallis/Byrd Cantiones of 1575 that Byrd was a pupil of Thomas Tallis, then the leading composing member of the Chapel Royal Choir. Byrd also worked in collaboration with two other Chapel Royal singing-men, John Sheppard and William Mundy, on one of his earliest compositions, a contribution to a joint setting of the alternatim psalm In exitu Israel composed for the procession to the font at the Paschal Vigil. As an item for the Sarum liturgy this was presumably composed near the end of the reign of Mary Tudor (1553–1558), whose Catholic beliefs impelled her to revive Sarum liturgical practices during her brief reign. In view of these contacts it is reasonable to speculate that Byrd was a Chapel Royal choirboy, though the surviving records do not name the choristers individually.