Search

Cellulose is the most important biopolymer in Nature and is used in preparation of new compounds. Molecular structure of cellulose is a repeating unit of β-d-glucopyranose molecules forming a linear chain that can have a crystallographic or an amorphous form. Cellulose is insoluble in water, but can dissolve in ionic liquids. Hemicelluloses are the second most abundant polysaccharides in Nature, in which xylan is one of the major constituents of this polymer. There are several sources of cellulose and hemicelluloses, but the most important source is wood. Typical chemical modifications are esterifications and etherifications of hydroxyl groups. TEMPO-mediated oxidation is a good method to promote oxidation of primary hydroxyl groups to aldehyde and carboxylic acids, selectively. Modified cellulose can be used in the pharmaceutical industry as a metal adsorbent. It is used in the preparation of cellulosic fibers and biocomposites such as nanofibrils and as biofuels. [ABSTRACT FROM AUTHOR]

Everyone agrees: it is difficult to talk about rhythm in music, or, for that matter, the temporal experience in general. Compared with spatial relations, which appear to us as fixed and graspable, temporal ones seem fleeting and intangible. As a result, the language of time and rhythm is complex, contentious, and highly metaphorical. Considering that theorists today continue to have difficulty dealing with the metrical and durational organization of music from the eighteenth and nineteenth centuries – our most familiar music – it should come as no surprise that theoretical writings from those centuries often present themselves as perplexing and in need of explication. Though their manner of formulation may at times seem odd or convoluted, these theorists nonetheless ask many of the same questions about musical rhythm that underlie current concerns: What is a metrical accent? How do the profusion of time signatures relate to each other? Do the groupings of measures create a sense of larger-scale rhythm? Can various durational patterns be organized according to some scheme or another? How does our understanding of musical rhythm affect performance, especially tempo, phrasing, and articulation? Like many other domains of music theory, rhythmic theories are largely formulated in relation to a distinct compositional practice. Thus when compositional styles change, theorists respond by modifying their conceptions and formulating new ones in order better to reflect such transformations in practice. The high Baroque style, with its motoric pulses, regularized accentuations, and dance-derived rhythms, induced early eighteenth-century theorists to focus in detail on the classification of various metrical and durational patterns and to begin accounting for that most elusive concept – metrical accent. [ABSTRACT FROM AUTHOR]

The most obvious trends in performing style over the first half of the twentieth century are easily summarised. Broadly speaking, early twentieth-century playing was characterised by the following habits: the sparing use of vibrato by string-players, its discreet use by singers, and the general avoidance of vibrato on woodwind instruments by most players except those of the French school; the frequent use of prominent, often slow, portamento by string-players and singers; the use of substantial tempo changes to signal changes of mood or tension, and the adoption of fast maximum tempos; varieties of tempo rubato which included not only detailed flexibility of tempo, but also accentuation by lengthening and shortening individual notes, and the dislocation of melody and accompaniment; and a tendency, in patterns of long and short notes, to shorten the short notes, and to overdot dotted rhythms. Instruments were also different from their modern equivalents in some ways – gut strings (used to a decreasing extent after World War I), wooden flutes (widely used except by the French school), French bassoons (not in Germany and Austria), and, though they have not been discussed in this book, the continued use of narrow-bore brass instruments. [ABSTRACT FROM AUTHOR]

INTRODUCTION One of the reasons for writing this book is a belief that early twentieth-century recordings can shed new light on the performing styles of the nineteenth century. The most obvious link is that many of the musicians who performed on early recordings were brought up in the nineteenth century, and their playing must include remnants of nineteenth-century style. The fact, for example, that Ysaÿe studied under Vieuxtemps and Wieniawski, and that Joachim played under Mendelssohn and was associated with Brahms, gives particular importance to their recordings. But the recordings of the early twentieth century have a more general relevance to nineteenth-century practice. Stated at its simplest, it is that none of the aspects of early twentieth-century style described in this book can have arisen overnight. In the use of vibrato and portamento, in flexibility of tempo, and in detailed rhythmic style, the performers of the early twentieth century can be heard moving towards what we now think of as modern style, and away from earlier practice – that is, the practice of the nineteenth century. This is no more than a statement of the obvious. In any period, performance is in a state of transition from the past to the future, and the early twentieth century is no exception. The difficult question, and the question of most interest to students of historical performance practice, is what aspects of early twentieth-century performance can be identified as surviving from the nineteenth century. [ABSTRACT FROM AUTHOR]

Many writers from the end of the nineteenth century and the early years of the twentieth century recommend flexibility of tempo, and reject the idea that a piece of music should be played at a constant pace. Hugo Riemann (1897), writing on expression, advises, First of all, in the matter of small changes of tempo, it may be remarked that hurrying implies intensification, and drawing back, the reverse; hence, as a rule, a slight urging, pressing forward is in place when the musical development becomes more intense, when it is positive; and, on the other hand, a tarrying, when it approaches the close. These changes must naturally be exceedingly minute in detached musical phrases, but can already become more important in a theme of a certain length; while for whole movements they are of such extent as to be seldom ignored in the notation. The singer David Ffrangcon-Davies (1906), in a book prefaced by Elgar, writes: 'An inelastic time-measurer, can never give us characteristic Bach or Beethoven, Mozart or Wagner. Metronome marks are never more than approximate at best.' Arnold Dolmetsch (1916) argues that alterations of time are 'as old as music itself', and states, 'It is obvious that emotional feeling, if there be any, will cause the player to linger on particularly expressive notes and to hurry exciting passages.' [ABSTRACT FROM AUTHOR]

Introduction In the reception of Haydn and Mozart, public and critical responses coincided significantly, even when their final evaluations differed; with the music of Beethoven the rôle of criticism was not to reflect (or deflect) public opinion but to inform and educate it. The Gazette's Beethoven criticism took a wide variety of forms, including descriptive analysis, literary portrayals and Romantic accounts of Pauline conversions to his music. Diverse as these approaches were, they shared a wish to mould public appreciation in favour of some of the most difficult music it had yet known. In comparison with Gluck, Mozart or Haydn, the number of articles on Beethoven which are independent of a performance is considerably larger, particularly if one includes Berlioz's Conservatoire reviews of 1838, which contained scant information about each programme, presenting instead an analytical survey of all nine symphonies. The Gazette offered its readers an extended justification of Beethoven from different perspectives, each providing a different way into the music. Its attitude was apparent from the outset; the composer's Romantic image as explored in Janin's ‘Le Dîner de Beethoven’ (GM 1/1–2: 5–12 Jan. 1834) was continued throughout its first decade. Such Romantic effusions may explain why, despite being welcomed as a member of the editorial staff in 1836, Fétis père contributed little of substance on Beethoven in the journal's entire lifetime. His views, as revealed in his own Revue musicale, were both too ambivalent and too professorial for Schlesinger. [ABSTRACT FROM AUTHOR]

While issues of performance technique, style and expression undoubtedly come to the fore in texts from the late sixteenth century onwards, earlier musicians cannot have been entirely unconcerned with interpretation, and the lack of written documentation does not necessarily mean that it was never discussed. Nevertheless, there is obviously a striking contrast between earlier treatises dealing with the rudiments required for performance and those later ones that are equally elementary but add recommendations on technique and style. Significantly, many of the vocal rules of the early seventeenth century are drawn directly from those few sixteenth-century writings which mention vocal technique. This could point either towards a codification of an existing practice or to a desire to justify rules for the present by earlier prescriptions. In any case, the noticeable expansion of treatises concerned with the actual practice of performance doubtless reflects the development of musica practica in Germany as the science of performance, something with its own rules and defining characteristics. Praetorius makes this explicit in his dedicatory foreword to Syntagma musicum, part 3, of 1619: So I have now in this third, and in the following fourth, volume compiled and written the most important things that a Kapellmeister who is a singing-master and musicus practicus will need to know, particularly in the present time when music has risen so high that one can hardly believe that it can come any higher. [ABSTRACT FROM AUTHOR]

Any study relating to performance practice is based on primary sources – treatises, letters etc – which either singly or as a group give us some inkling of the context and specifics of historical performance. Problems often arise, though, for we cannot always be sure of the background of the writer concerned, his motives – benign or otherwise – or his relation to his contemporaries. Moreover, we are often equally unsure of the specific musicians to whom he addressed his remarks, or of who actually read his works. In the case of the present study there are certain factors which minimise these problems. First, the treatises concerned are, on the whole, chosen for their express relation to practical music instruction in a specific, semi-standardised education system; most writers belong to this system as practising teachers and musicians. There are sufficient similarities between the works and sufficient instances of direct plagiarism and reprinting to suggest that they offer a realistic picture of musical education and are thus not merely the speculations of a few eccentric cantors. Indeed some writers seem positively to be proud to have drawn their material from important authors; evidently adherence to tradition was often more desirable than originality. On the other hand, it must continually be stressed that the body of surviving literature is no substitute for what actually happened in public and private instruction; at most it offers a trace of what successive musicians and teachers themselves must have read, and – to a lesser and vaguer extent – a summary of what each may have consciously experienced in practice. [ABSTRACT FROM AUTHOR]