Walking into the shop Sebastian rubs his hands together then breaths heat into his palms and rubs them together again. In preparation for the cold weather he wore a dull orange wool jersey, a dark green beanie, and his usual blue denim jeans with leather tramping boots. As he looked around at the many musical instruments he remebers why exactly he was stopping in this shop, so slinging off his backpack he takes out an old herb-lore book specifically titled 'Music, Magic and Maturing Plants by Dennis Greenthumb". Walking towards a row of classical instruments he pages through the book to a section he bookmarked, about Cellos and their music's affect on plant growth.
Sebastian's mind wanders to a memory from his travels through Muggle Europe, visiting France and Italy. In Italy he took time out of sightseeing to go see two men preforming covers of popular muggle songs on Cellos. He recalls how the music touched his soul in a way he'd never experienced before, having never been very interested in Music while growing up. The memory stuck with him for a long time, and it was finding this old book in Diagon alley a week ago that he knew learning to play the instrument would be a great addition to his skills. While not useful in combat or dueling, enchanted instruments can affect the environment around him, and were very useful for those growing magical plants, caring for magical creatures, and even gave a small boon to potion making, when in the hands of a true master.
Coming back to reality Sebastian shakes his head and strolls through the rows of Cellos, looking for the one that fit his tastes and body best, testing them to find out which he was most comfortable with, sitting on a seat while testing the feel of the bow in his hands etc. He was very busy and, while distracted from the world around him, his senses were still actively hearing and testing the air in the shop.