Robert and John Harper were very small-scale piano builders in New York during the 19th Century. Although the relationship between the two men is not clear, it appears they were either brothers or very close relatives, often sharing the same business address over the years of their careers.
John Harper is first listed at 265 Avenue 6, New York City, in 1846. In 1849, Robert Harper joined the firm, then located at 277 Avenue 6, and the name was changed to 'John Harper & Company'. Robert Harper left the firm and moved to Fordham, New York in about 1851 to establish his own firm. Robert continued to build pianos and possibly melodeons under his own name in Fordham, New York until sometime in the early 1860s. John Harper continued building pianos under his own name in New York City until about 1855.
All extant instruments we have seen by John or Robert Harper have been small, well built high grand square grand pianos. Pianos by these makers are exceedingly rare today.