Sources are one of the fundamental pillars of any kind of historical performance practice of music. Particularly for those of us who play polyphonic instruments, reading from the same pages that were used by players in the 16th century – for the purposes of the present study – draws us closer to the essence of the music we are playing, or so we believe. It obliges us to see the music as they did, and it requires us to make many of the same decisions about many aspects of performance that were faced by the musicians who created the pieces we play, or who were its original consumers. From my own perspective as a lutenist and vihuelist, it is quite surprising to see the large number of contemporary harp- sichordists and organists who interpret this by playing primarily from carefully edited modern editions, written in modern notation. The contemporary lute world is the reverse: nearly all modern lutenists play from tablature, from the original notation, whether in facsimile reprint or in a modern typeset version of the original. This anomaly of notational practice is the first of the two main discussions within this essay; the other concerns that uniquely Spanish prac- tice of the 16th century of having music ‘para tecla, harpa y vihuela’ that could supposedly be played on keyboards, harp and lute from the same notation. Tablature of one kind or another was the common notational language for keyboards and other polyphonic solo instruments during the 16th century. The exact extent of the surviving repertoire of works in tablature from before 1600 has not been calculated, but I would estimate it to be in the vicinity of 20,000 works, a substantial amount of music and a repertoire that is large enough not to be ignored. In this essay I wish to discuss some of the broader vision and distilled conclusions arising from a substantial research project about tablature in the 16th century. The project was actually based on all Western tablatures prior to c. 1750 that will soon be published as a single volume of encyclopaedic proportion representing tablatures for over forty...