This is the 5823rd most frequent Japanese word.
ひたっ
"ひたっ" alone is not a standard Japanese word. It may be a colloquial or informal variation; clarity on its meaning would require additional context.
In this sentence, 'ひたっしていた' is derived from 'ひたる', meaning to be immersed or absorbed in something.
彼は本にひたっしていた。
He was absorbed in the book.
Here, 'ひたっしていて' indicates that the subject is deeply engaged or focused on music.
彼女は音楽にひたっしていて、時間を忘れてしまった。
She was immersed in music and lost track of time.
'ひたりました' in this sentence shows a reflective absorption into the experience of nature's beauty.