This thesis aims to address the subject of tempo as one of the most important components of classical music. The work consists of two parts.The first part is an overview of the aesthetic background and the factors which influence the choice of tempo in the music of the beginning of the 19th Century. It is based mostly on the testimonies of Beethoven and his contemporaries. In addition, I will briefly describe the philosophy of interpreting tempo markings at the end of the 19th and the beginning of the 20th Century. Such generalizations are possible due to the invention of recording technology at the end of the 19th Century. I shall also describe briefly the impact that recording has had on the interpretation of music.In the second, practical part of my work, I shall observe and analyze two different recordings of the first movement of Ludwig van Beethoven's First Symphony. I have chosen two of the most prominent conductors from the latter half of the 20th Century - Herbert von Karajan and Claudio Abbado. I will analyze their tempo choices throughout the chosen movement by measuring them and putting the results in a table together with remarks about the formal structure of the music.I will compare, analyze and comment on the two interpretations of these two important conductors and seek to explore the aesthetics behind their approach to tempo. I will also provide background information: factors that - consciously or subconsciously -seem to have influenced these two artists.