Saving new files

I created a new file based on Michael Card's "Celebrate the Child Who is the Light", which I gave a new range of SATB (key changes every verse in original) to suit my small ensemble for presentation on Jan 22 (2 practices). I was interrupted and when I came back, there was no trace - and I looked everywhere - of the work carefully crafted, somewhat syncopated. It was a huge debt of patience and diligence. This was only the second I have done on a new Mac. I bought the new Mac because I couldn't upgrade to Muse4 on the old. Now I am regretting that I didn't do the old version, which I have used weekly to generate accompaniments of my choir's presentations. (We currently have no accompanist except me, and choir prefers direction). Once, in the older version, I faced a similar dilemma, and carefully worked my way to systems which saved/contained the files in the long alphanumeric codes, I don't see that in this new M2 machine. Do I have a chance of retrieval?