This thesis ventures into the world of twentieth century chamber music, specifically the trios written for flute, cello and piano. The first chapter discusses the history of the trio, tracing its development from the trio sonata of the Baroque Period to the accompanied sonatas and specifically the sonatas with flute and cello obbligato. Following the unpopularity of the genre throughout the Romantic period, its greater prominence in the Twentieth century is discussed, mentioning specific groups through whom the repertoire has been extended. Forty trios are grouped according to compositional styles. Six trios, each representing an example of a specific style period, have been selected for more detailed discussion, with particular reference to the various ways in which a sense of unity is achieved in each trio. The English composer Eugene Goossens uses impressionistic images, whole tone and chromatic scale patterns and other motifs to unify his trio: "Five Impressions of a Holiday". Nikolay Iosifovich Sil'vansky's "The Hedgehog and the Nightingale" is based on a Russian tale by Juri Jarmicha and uses a narrator. The three characters are represented by specific motivic and / or thematic material which is used throughout the trio. Günter Raphael's Trio-Suite op 44 is the only cyclic work unifying the two outer movements, without repeating any additional motivic material. Jean-Michel Damase condenses some of the material introduced in the opening Prelude in both the two Largo's and the two Arias in his "Sonate en Concert" of 1950. Karl Julius Marx builds his entire "Trio op 61" on a flexible six-note motif. Various movements in the trio" Vox Ba1aenae" by the American George Crumb are 1inked through the use of motives and characteristic instrumental colour. A comprehensive list of 180 twentieth century trios has been compiled, including details of dedications, commissions and first performances. 163 composers from twenty countries, are represented.

Constantin, grâce à sa prise de pouvoir au début du IVe siècle, permettra l'essor d'un nouveau type de dévotion, consacré aux hommes et aux femmes ayant rendu l'âme en défendant leur ferveur pour le Christ et son Père. Ainsi, Laurent, persécuté à Rome en l'an 258, deviendra au siècle suivant la figure prédominante du martyre dans la ville éternelle. Ce mémoire cherche à comprendre comment se développera son culte et quelles sont les raisons qui mèneront son martyre à la primauté dans la capitale romaine. En étudiant les sources littéraires et épigraphiques, notamment sous la plume de Damase, Ambroise, Prudence et Augustin, ainsi qu'en explorant les informations archéologiques sur la construction d'églises dévouées à Laurent, nous en sommes venus à la conclusion que le martyr romain a contribué à la création d'une mémoire collective chrétienne qui correspondait au besoin identitaire de l'Urbs, dans ce passage d'un empire « païen » à un empire chrétien. Cette création d'une mémoire collective repose sur la sacralisation du territoire par l’empereur Constantin et l’évêque romain Damase, l’introduction de nouveaux rituels et dans la foulée, de l’instrumentalisation de Laurent et du culte des saints par les auteurs anciens dans leur élaboration de l’identité chrétienne de la ville de Rome. / Constantine, with his seize of power in the early fourth century, has allowed the growth of a new form of devotion dedicated to the men and women tormented because of their beliefs in Christ and his Holy Father. Thereby, Lawrence, persecuted in 258 A.D. in Rome, has become the main figure of martyrdom in the Eternal City during the following century. This master's thesis aims at comprehending how the cult of Lawrence's unfolded and why it became the predominant martyr cult in the Roman capital. By studying literary and epigraphic sources, especially Damasus, Ambrose, Augustine and Prudence, as well as the archaeological data on the construction of the churches dedicated to Lawrence, we came to the conclusion that the Roman martyr helped establish a Christian collective memory corresponding to the identity needs of the Urbs in this period characterized by the passage of a "pagan" empire to a Christian empire. This creation of a collective memory is based on the sacralisation of the roman territory by the emperor Constantine and the roman bishop Damasus, on the introduction of new rituals and on the instrumentation of Lawrence and the cult of the saints by the ancient writers in their elaboration of a Christian identity for the city of Rome.