As a first-class music transcriptionist with multiple years of experience, I have the skillset you need to successfully execute this task. I'm adept at not only writing sheet music, but also familiar with the very instruments you require transcribed: the sousaphone, euphonium, trumpet, and trombone. This familiarity not only informs my competence in transposing music for Bb and C instruments but enhances the overall quality of my deliverables.
My work is much more than rearranging notes and melody lines as accurately as possible - it's about conveying the emotions and stylistic elements that make each performance unique. As such, your requested dynamics marking will be carefully noted in my transcription, ensuring your brass ensemble can replicate the nuances of the performance in the video.
While a week may seem tight, I've built a reputation around fast yet precise delivery that meets or exceeds client expectations. Even more importantly, my process prioritizes open communication and collaboration to ensure that my work aligns directly with your vision. Combining my strong time management skills with your timely feedback we can effectively overcome this challenge for better results.
In conclusion, choosing me for this task is choosing reliability, musicality, and a passion for excellent service delivery. Let's work together to create sublime sheet music that will give your brass ensemble an outstanding performance!