<Li> Elizabeth Daily as vocal effects for Lorenzo Odone </Li> <P> Principal photography for Lorenzo's Oil began on September 9, 1991 in Ben Avon, Pennsylvania . </P> <P> Possibly to emphasize the "Everyman" aspect of the plot (the notion that a cure could affect families and individuals anywhere), many smaller roles were played by inexperienced actors or non-actors with unusual physical features and mannerisms . For example, the poet James Merrill was noticed by a casting director at a New York public reading of his poetry . His rarefied speaking cadences were utilized in a symposium scene in which he played a questioning doctor . </P> <P> The film features Allegri's Miserere, Edward Elgar's cello concerto, as well as Barber's Adagio for Strings and Mozart's Ave verum corpus K. 618 . </P>

What was lorenzo's oil and why was it so special