Final answer:
It is likely false that 'Joaquin' did not use preexisting melodies in his sacred works since many composers incorporate traditional hymns or chants into their compositions. The reference to LibreTexts™ suggests that even composers conducting their own works may not offer the best interpretations, which aligns with the common practice of reinterpreting sacred music.
Step-by-step explanation:
The statement 'Joaquin did not use preexisting melodies in his sacred works' is likely false. Composers of sacred music have often incorporated preexisting melodies, such as traditional hymns or chants, into their compositions. This practice allows them to connect with a familiar spiritual musical language while adding their own creative touch. However, without specifying which 'Joaquin' the question is referring to, it's difficult to provide a completely accurate answer. Generally, composers, even when conducting their own works, as mentioned by LibreTexts™, may not always deliver the best interpretations compared to other conductors who might bring fresh insights into the music.