談論古典音樂 (Classical Music)時，大家先想到的可能是德國、法國、義大利等等古典音樂盛行的國家，丹麥與古典音樂圈好像連結不太起來，提到丹麥的音樂家，如果不是對丹麥音樂家有研究過，大家可能思考很久之後才會想到丹麥作曲家兼指揮的尼爾森 (Carl August Nielsen, 1865-1931)，倘若為非愛樂人士或者是對古典音樂如果沒有更多瞭解或涉略，尼爾森之於大眾來說也是非常陌生的作曲家，但是，長號跟丹麥音樂家的淵源可是非常密切的，不過就像是尼爾森之於古典音樂圈一樣，長號界對於丹麥作曲家也是不太熟悉，甚至演奏過許多丹麥作品後，經過老師的提點才發現自己演奏過丹麥作曲家的作品。
自20世紀以來，長號 (Trombone)的獨奏作品被大量的創作及發表，除了活躍於古典音樂圈的音樂家之外，本論文所探討的丹麥當代作曲家索倫‧旭嘉 (Søren Hyldgaard,1962-2018)在古典音樂圈並不算是位很熟悉的一個音樂家，旭嘉多數的創作在於電影配樂及新世紀音樂，我們熟悉的「古典音樂」作品為數不多。
本論文將以索倫‧旭嘉的《北方之聲長號協奏曲》作為主題，《北方之聲長號協奏曲》為旭嘉在2001年時為當時丹麥國家管弦樂團 (Danish National Symphony Orchestra)長號首席耶斯波‧玉勒 (Jesper Juul Windahl, 1973-)所創作的長號獨奏曲，本論文分總共分為六個章節，第一章為緒論討論研究動機目的及研究方法討論；第二章將會討論長號的發展史與臺灣近年來經常被演出的長號曲子及學生音樂比賽中學生所挑選的自選曲；第三章為作曲家生平及創作理念闡述；第四章為《北方之聲長號協奏曲》作品分析；第五章為《北方之聲長號協奏曲》演奏詮釋討論；第六章為結論及筆者資料的搜集來源，筆者也期待此論文能為長號在臺灣的發展盡一點心力。

Speaking of classical music, nations such as Germany, France, and Italy where classical music prevails would normally come into people’s minds that makes people deem that Demark has no relation to the classical music circle. Even if having some research on Danish musicians, people might think of Carl Nielson (1865-1931), a Danish composer and director, in a moment. Without a thorough understanding of classical music, Carl Nielson is a total stranger to the public. Nonetheless, trombones and Danish musicians have a strong and inseparable connection. However, as the relation between Nielson and the classical music circle, most trombonists are not completely acquainted with Danish musicians. Some peoples have ever performed works by Danish composers until professor’s reminder.
Since the twentieth century, a great number of works for the trombone have been created. One of them is Concerto Borealis by Danish contemporary composer-Søren Hyldgaard (1962-2018), A musician who is not very familiar to the classical music circle whose classical music compositions are enshrouded by his numerous remarkable film scores and meditational New Age music.
This thesis is under the topic of Concerto Borealis. Which was dedicated to Danish trombonist Jesper Juul Windahl (1973-), a principal trombone at the time at the Danish National Symphony Orchestra in 2001. written in Six chapters, The first chapter is the introduction discussing the motivation and methods. The second chapter embodies the development of trombones, frequently performed trombone repertoire, and electives of students' music competitions. The third chapter is composer’s biography and idea from works. The fourth chapter covers the analysis of Concerto Borealis. The fifth chapter encompasses the interpretations and performance practice of this work. The sixth chapter contains the conclusion and the bibliography. Through the thesis, wish to dedicate myself to the promising future of trombones and trombone music in Taiwan.

〈一〉、中文書籍
張禮宗。《長號演奏理論之分析》。臺北：旗力資訊股份有限公司，1996。

〈二〉、外文書籍
Taruskin, Richard. “The Oxford History of Western Music, Volume 5: Music in the Late 20th Century.” Oxford University Press, 2009.
Burkholder, Peter. Grout, Donald. Palisca , Claude . ‘‘A History of Western Music’’ Ninth edition. W. W. Norton & Company, 2014.

〈三〉、樂譜資源
Hyldgaard, Søren. Concerto Borealis (Arranged Trombone for Piano). Edition Samfundet, Frederiksberg C, Denmark. 2001, rev. 2005

〈四〉、電子資源
Burlingame, Jon. ‘‘Danish Film Composer Søren Hyldgaard Dead at 55.’’ 2018. Accessed April 27, 2021.
http://www.filmmusicsociety.org/news_events/features/2018/050818.html
Hyldgaard, Søren. ‘‘Concerto Borealis’’. Accessed January 22, 2021.
https://www.edition-s.dk/music/soren-hyldgaard/concerto-borealis
Jensen, Niels. Christensen, Louis. Nielsen, Svend. ‘‘Denmark.’’ 2001. Accessed July 2 , 2020.
https://0-doi.org.opac.lib.ntnu.edu.tw/10.1093/gmo/9781561592630.article.07563
National Student Competition of Music. Accessed November 8.
https://web.arte.gov.tw/music/

〈五〉、有聲資源
Hyldgaard, Søren. ‘‘Rapsodia Borealis’’ on T-Bone Music. RONDO RECORDS, 2003
——. ‘‘Rapsodia Borealis’’ on Romantic Trombone Concertos. Dacapo Classical, 2006.
——. ‘‘Rapsodia Borealis’’ on Canticles. AMSTEL CLASSICS, 2011.
——. ‘‘Rapsodia Borealis’’ on 2003 WASBE. MARK RECORDS, 2012.
——. ‘‘Rapsodia Borealis’’ on Copenhagen Recital. BIS, 2014.
——. ‘‘Rapsodia Borealis’’ on Masterbrass IV. Aldebaran Editions, 2015.
——. ‘‘Rapsodia Borealis’’ on Outrageous Fortune. Toccata Classics, 2019.