Inspired the title of John Singer Sargent's painting:

Carnation, Lily, Lily Rose
1885-1886

Joseph Mazzinghi (1765-1844) composer. The only thing I could find on him was that he arranged songs for the theater and operas in London as well as writing popular music.
  Ye Shepherds Tell Me
music sheets (over 500 kb total)
jpg: National Library of Australia

The above version of the song was published by Melbourne: Allan & Co., ca. 1892 -- after Sargent's painting of 1885-1886. I found an earlier version which is slightly different published around the time Mazzinghi would have written it (New York:  Firth & Hall, [1832-47]) (www.lib.unc.edu/music)

View image of cover earlier version.
View p. 2.
View p. 3.
View p. 4.
View p. 5.
View p. 6.
View p. 7.

The only difference of note is the last stanza of the later version is missing from the earlier version, as well as the punctuation of the line "Carnation lily, Lily rose" -- earlier version; compared to "Carnation, lily, lily, rose" -- later version.

The song was exceptionally popular in the UK and was probably played as a piano duet (which Sargent often did) with maybe Alma Strettell as the other player and a third singer joining the two. Alma, who joined the Broadway group in '86, was as much a fanatic about music as John and the two had been friends since Paris.

Alma Strettell
1889

However much fun they had at Broadway with this song, it's interesting to note its popularity was widespread. In an excerpt from a paper from Martock (located between London and Exeter) dated 1895, mentions the song being sung at a club.
 

April 19-1895

Football Club Dinner. To close the football season, after a friendly match between teams captained by Mr. G.A.Cox and Mr. T.Hayman on Wednesday afternoon, a dinner was held at the Langport Arms Hotel, under the presidency of Francis Meade, when the catering of Mr. and Mrs. Barling gave the utmost satisfaction.

A large company of members and friends were present. The usual toasts were duly honoured, " Success to the Football Club" being proposed by the Chairman in appropiate terms, Messrs. Burmingham (the hon. sec.), Cox, and Hayman responding.

Some capital songs were sung during the evening by Messrs. Guy Barrington, G.A.Cox, Meredith, J.F.Cox, W.Rowe, and Dennett.  The trio, " Ye shepherds, tell me," was sung by Messrs. G.A.Cox, C.Morris, and J.F.Cox,

A very pleasant evening was spent.  The match in the afternoon was won by Mr. G.A.Cox’s team by four tries to two.
(Martock - Marijke Huysse)

Francis Davis Millet

A Difficult Duet
1886

Old Harmonies
Date?