mass

From the magazine America "A Catholic Review of the Week" of June 17, 1916:

"Our Catholic musical inheritance is widely utilized by secular organizations. A favorite production is Verdi's Requiem Mass which has frequently been presented by opera companies and choral societies but never perhaps on so large a scale as in the first outdoor presentation of it in New York under the auspices of the National Open Air Festival Society. The chorus consisted of 1,200 singers selected from among the leading choral societies of New York, the accompaniments were played by an orchestra of 120 and among the soloists were four world wide celebrities: Giovanni Zenatello, Mme Maria Gay, Miss Lucille Lawrence and Léon Rothier. All these immense forces were under the leadership of Mr. Louis Koemmenich. To make it possible to carry out the production on a scale of magnitude such as will inaugurate a new era in the musical development of this country, the New York Polo Grounds were chosen and a huge stage constructed with a sounding board large enough to reflect the sound of the many voices. It was an ambitious undertaking crowned with deserved success."
books.google.com/books?id=elY_AQAAMAAJ&pg=PA243&l...
This took place on June 4, 1916, backed by the New York Philharmonic, and was touted as the "greatest enlistment of voices in interpretation of an oratorio ever employed."
query.nytimes.com/mem/archive-free/pdf?res=F30717F93E5F17...
"Léon Rothier (December 26, 1874 – December 6, 1951) was a French musician, predominantly an opera singer in the bass range,[1] who reached the peak of his powers in the early 20th century at New York's Metropolitan Opera."
en.wikipedia.org/wiki/L%C3%A9on_Rothier
Lucille Lawrence's name also appears in publications as Lucile Laurence and Lucile Lawrence. One newspaper account describes her as "a Kentucky girl who has sung prima donna roles in Italy the last 2 years."
fultonhistory.com/Newpapers%20Disk2/Auburn%20NY%20Citizen...
"Louis Koemmenich [aka Louis Kömmenich] (1866–1922) was an American composer and conductor born in Germany; he came to the United States in 1890. He was active as a choral conductor, and as a result wrote mainly choral music, although some of his songs are also extant." At this time, he was conductor of the Oratorio Society of New York. en.wikipedia.org/wiki/Louis_Koemmenich
Zenatello and Gay, a couple off the stage, were seen earlier, see notes under:

Thanks alot artolog! Its great to have the complete names of the performers and the event depicted here. We will add more details to the description when we update.

For some reason this photo looks to me like it is of a chaplin holding a service

Well spotted - its the wrong photo with the metadata or vice versa. I'll look into it and sort it out. Thanks for the heads up!

Sorted now, I hope

According to the caption on the following photograph, this building was demolished in 2008:

So that explains why I couldn't find the location of it. I was scouring the Drouin region in Google Maps & street view trying to find it!