A fermata tells the player they can hold the note as long as they feel is appropriate and not a specified length of time. If you want a note held a specific length you should notate it exactly. If you want a specific tempo you should notate it. You can place a fermata over all the notes of a measure, but you can't rely on them all being the same length. Convention is to place the fermata over ...
I am taking part in a music theory course on Coursera, and I could not understand the difference between a tie and a fermata. Could someone please explain it to me?
Why do composers use fermatas? - Music: Practice & Theory Stack Exchange
There's an infinite debate about how music can actually be considered as a form of language (as in communication). Still, the common analogy, also used for music education, passes through voice expression. A "fermata" is similar to a "dramatic pause", but, instead of having an actual silence (a rest), you just keep the "sound of your voice" for a longer time to increase its "dramatic effect ...
piano - How long do you hold a fermata? - Music: Practice & Theory ...
Using a fermata on both cello notes would seem wrong, and placing a fermata on the triangle part doesn't really make much sense. I could use some combination of fermata for the strings, and ritenuto for the cello and triangle, (which is what I have at the moment) but this seems yuck; unnecessarily awkward and potentially confusing:
Ritenuto / Fermata / Tempo change - Music: Practice & Theory Stack Exchange