The visitor probably remembers the fact that there are no extant transverse flutes from the Middle Ages, a fact that leaves us unable to know how they sounded and how they were played. Besides that, just few examples of music written at that time for the flute were found - which leaves us in the dark when we try to figure out the characteristics of the flute repertoire back then. The Renaissance doesn't present such problems with the same depth: Renaissance flutes and Renaissance flute repertoire were both found and are being analysed by musicologists. Those sources, however, are not the only useful ones, for images and texts referring to the flute (the main kind of source we rely on when it comes to the Middle Ages) were also found.
Most historians agree that the Renaissance lies between the fifteenth and the seventeenth centuries. Anne Smith (the author of the chapter dedicated to the Renaissance flute which belongs to John Solum's book "The Early Flute"), however, defines the Renaissance flute as the flute played in Europe between 1500 and 1670, being the last date an estimated year for the appearance of the baroque traverso. Smith describes the Renaissance flute as having a more or less cylindrical bore, six finger-holes and one embouchure hole.
Only rarely is the flute found in fifteenth-century paintings. The instrument is found more frequently in paintings of the next century. Those paintings suggest that the flute was played in two very different contexts, the military context being one of those two. Sources point out that the transverse flute became a traditionally military instrument around the sixteenth century. In 1467, Swiss troops achieved success in the battlefield by employing an extremely disciplined formation that was not only strong in defense but also movable when attacking. Testimonies related that those troops marched in perfect synchronicity, just like a deadly corps de ballet, accompanied by a fife (a transverse flute very similar to that one described by Annie Smith) and some drums. News about that original battle strategy spread all over Europe by the end of the fifteenth century.
This image belongs to a German manual of military science and law published in 1555. In it, we see a fife player (his back turned on us) and a drummer. Hanging on the fife player's back, his case, inside of which four instruments could fit: a long fife, two middle-sized fifes and another shorter in size.
Illustrations of battle situations dating from the sixteenth century do not represent the fife very uniformly: its size was highly variable (from 2 to 3 feet) and the number of finger-holes could vary from seven to eight. Thoinot Arbeau (1519-1595) wrote in his dance manual titled "Orchesographie" (1589) about a fife which characteristics are closer to those of the fife of our days: a little transverse flute with six finger-holes and a very narrow bore, which contributed to the brilliant timbre of the instrument. Arbeau also points out that the music played by military fife players was improvised.
A richly illustrated edition of the first known treatise on instrumentation was printed in Basel in 1511. Its title is "Musica getutscht" and it was written by Sebastian Virdung (c.1465-1511), a priest. Virdung was the first musical theorist of the seventeenth century to mention flutes of any kind. He uses the word "Flöten" to refer to recorders, and the word "Zwerchpfeiff" to refer to the military fife (he doesn't mention any kind of transverse flue played outside the military context). On the other hand, Martin Agricola (c.1486-1556) published in Wittenberg in 1529 (and also in 1545, in a revised edition), his "Musica instrumentalis deudch". Agricola writes about a few kinds of transverse flutes - the "Schweitzerpfeiffen" (Swiss fifes) and the "Querfeiffen" or "Querpfeiffen" (transverse flutes or transverse fifes) -, but he describes another kind of context for the use of those flutes, one very different from the military context.
A richly illustrated edition of the first known treatise on instrumentation was printed in Basel in 1511. Its title is "Musica getutscht" and it was written by Sebastian Virdung (c.1465-1511), a priest. Virdung was the first musical theorist of the seventeenth century to mention flutes of any kind. He uses the word "Flöten" to refer to recorders, and the word "Zwerchpfeiff" to refer to the military fife (he doesn't mention any kind of transverse flue played outside the military context). On the other hand, Martin Agricola (c.1486-1556) published in Wittenberg in 1529 (and also in 1545, in a revised edition), his "Musica instrumentalis deudch". Agricola writes about a few kinds of transverse flutes - the "Schweitzerpfeiffen" (Swiss fifes) and the "Querfeiffen" or "Querpfeiffen" (transverse flutes or transverse fifes) -, but he describes another kind of context for the use of those flutes, one very different from the military context.
The image above belongs to Virdung's "Musica getutscht". The fourth instrument from the top to the bottom was mentioned in the previous paragraph: it's the "Zwerchpfeiff". Right below it, four instruments from the family of the recorders (or "Flöten", according to Virdung). The two instruments on the top are not flutes, but shawms ("Schalmey"), the predecessors of the oboe.
I have mentioned the existence of two different contexts for flute-playing just a few paragraphs back. I've written about the military context. The other one is the one described by Agricola's writings: the court and the private residences - the chamber music (or, to be more specific, consort music). Consort music was written for a formation of instruments that belonged to the same family. If we take a flute for example, a consort of flutes would be formed by flutes of the same kind, but of different sizes (in order to explore low and high pitches), and each one with its individual melodic line.
Agricola had in mind a flute consort in which three instruments of different sizes figured: one bass flute, another one of intermediate size which could play the tenor or the alto part, and a smaller flute to play high pitches. Philibert Jambe de Fer (c.1515-1566) describes in his "L'Epitome musical" (published in Lyons in 1556) a four-flute consort in which instruments of two different sizes were combined: one bass flute and three smaller flutes of the same size - versatile instruments capable to play in different registers. The first collection of music written for this kind of four-flute consort was published in 1519. That fact shows that Jambe de Fer was writing about a practice that was already common when it comes to music for flute consorts of that time.
English Renaissance music played by a Renaissance flute consort. That consort (the Flötten Consort Stuttgart) is similar to the one described by Agricola. It has three instruments: one bass flute and two flutes of similar size (opposing to Agricola's description of a flute consort of three flutes of different sizes).
It seems that the transverse flute has reached great popularity - as well as a certain level of predominance - at the middle of the seventeenth century. Such hypothesis is sustained by the numbers found in inventories of the musical instruments that belonged to certain courts of that time. One inventory written in 1589 referred to the musical instruments possessed by the court of Baden-Württemberg (located in Stuttgart): 220 transverse flutes, 48 recorders, 113 cornetts and 39 viols. The transverse flute also became popular outside of the court. Members of the bourgeoisie and amateur musicians among the nobles of both sexes were playing it in Italy, France and Holland.
Despite the large number of transverse flutes found in court inventories all over Europe, playing music in flute consorts seemed to be considered some kind of French expertise in the sixteenth century. Frenchmen called for themselves the status of the best flautists in Europe - they also didn't really like the term "German flute". That wasn't mere vanity: French flautists held very important musical positions outside France, a fact that attests the high quality of their performance.
The flute wasn't limited to military music and flute-consort music. It also appears in groups of diverse instruments. Such groupings weren't uncommon in the context of religious and private music. In 1563, in the Bavarian court located in Munich, Orlando di Lasso (1532-1594) started to use string instruments in religious music and, after that, started to use all kinds of instruments and voices.
This painting (painted in 1520, approximately) shows three women practicing chamber music, in a private context, in a group of diverse instruments: the lute, the flute and the voice.
Filadelfio Puglisi, a researcher who has studied the Renaissance flute in depth, had access to a Renaissance flute collection found in Verona, Italy. After comparing those flutes he found out some common characteristics between them:
1.In most cases, the embouchure hole was oval and smaller than the embouchure hole of baroque flutes;
2.To make fingering easier, the six finger-holes were placed in two groups of three;
3.All the holes were aligned, a feature that allowed the flute to be held either to the right or to the left;
4.The bore was semi-cylindrical;
5.The walls of the instruments were relatively thin, a feature that contributed to their lightness;
6.The pitch of the Verona flutes varied a lot, but two great pitch groups were found out: one in A=435hz (the "Kammerton", employed in private and festive music) and the other one in A=410hz (the "Chorton", employed in religious music). The Chorton was a whole tone lower than the Kammerton and the group of flutes in A=410hz was bigger than the other group in A=435hz.
Some of the Renaissance flutes found in Verona.
Instrumentalists tried to cultivate a singing style while playing - in other words, they wanted to make their instruments produce sounds which qualities resembled those of the human voice. Agricola encouraged the use of vibrato and many sources point out that instrumentalists considered that vibrato (produced by the air column or the fingers) was an essential element of the sound and its expressiveness. Renaissance flautists also gave great importance to the articulation of the sounds. As in speech, a clear articulation was considered indispensable for a good performance. Jambe de Fer encourages his readers to articulate every single note - even the fastest ones - saying that "he who doesn't articulate every syllable while giving a speech sounds like he is drunk and, therefore, such attitude would produce a poor effect in music as well". Another important aspect of Renaissance music-making was "diminution" - or improvised ornamentation of a melodic line. The instrumentalist had to be capable of improvising on the given melody, making his musical discourse even more rich.
Thanks to the fact that there are extant Renaissance flutes and Renaissance flute-music, we can paint a clearer portrait of the flute of that time - a much clearer portrait than the one of the Middle Ages. However, it would be unwise to think that the knowledge we have is solid enough to make exact assumptions about the subject. The extant instruments are very fragile and, due to this fragility, just a few researchers have access to it. That means that we don't have many different points of view on the subject and that only a small number of individuals were able to make reliable replicas of those instruments and, therefore, to learn how to play them accordingly to the stylistic conceptions of the Renaissance. Besides that, it is not that simple to come up with the accurate dates of the making of the extant instruments - some of them were reevaluated as seventeenth-century replicas. What we know about the Renaissance flute is based on the vision of a small number of specialists, people in which we chose to trust.
Main sources:
POWELL, Ardal. The Flute. New Heaven and London: Yale University Press, 2002.
SOLUM, John. The Early Flute. Oxford: Oxford University Press, 1992.