Agnus Dei by Samuel Barber...used for state funerals since Roosevelt in the USA.
Miserere by Allegri: it is rather a paschal chant, usually sung by castrati. Jealously kept for Easter at the Sistine Chapel, it was reconstructed "by ear" by Mozart, which allowed the Miserere to enter history. The tones are extreme and the rhythm, which seems long at first, puts you in tune. Recommended in cases of depression or significant stress, on an individual basis.
Brahms' German Requiem is also very emotional.
Or in a completely different register, Mistral Gagnant by Renaud will be particularly touching for a young person.
