Music travels across the past in the form of composers borrowing from each other. Such musical borrowings and quotations involve not only the use of melodic materials but also musical structures, texts, symbolism and other types of inspiration. The pre-existing musical idea being used is linked to a specific memory of a particular composer and time. The artistic allusions of composers connect the present and the past. Music also travels across the present and into the future. The outcome of contemporary composers borrowing from each other influences the present period and affects later composers' musical inspiration, i.e., it affects future composers, and therefore, the future. Composers frequently refer to melodies or musical idea from contemporaries and reinterpret them in their own compositions. This is largely because composers do not write in isolation and have been inspired and influenced by contemporary musicians and cultural contexts. However, these musical borrowings sometimes raise questions about the composers' creativity and authenticity. This is largely due to the nature of inspiration and imagination, which determines who or what is original. With this in mind, why do composers still borrow musical ideas despite the risks involved? In what ways do they overcome criticism and demonstrate the excellence of their own compositions while referring to the work of others? In what ways do artistic allusions influence new compositions? In this dissertation, I attempt to examine these questions and address the reasons for and the effects of musical quotations and allusions.