Nothing about Wagner’s epic “Ring” cycle is small in scale, but when a would-be impresario came up with the idea of staging it in West Hartford, Conn., he envisioned replacing its massive orchestral forces with the digital sounds of sampled instruments.

The idea of replacing musicians with machines in opera, a proudly acoustic art form that glories in its traditions, was seen as sacrilege by some music fans, players and union members, who took to social media to denounce the project and call for boycotts. That has been followed by what some singers in the cast viewed as strong-arm tactics: some received an email from musicians in the Chicago Lyric Opera Orchestra warning them that if they did not resign, “the live musicians of this country will remember you for the rest of your career and treat you as a traitor to our art form.”

The warning had an effect. “Coincident with my own concerns, my own artistic concerns, I have chosen to withdraw,” Robert Brubaker, the tenor who was to have sung Mime, a role in which he has won praise at the Metropolitan Opera, said in a telephone interview this week from Barcelona, Spain. “But,” he added, “I find it distressing to be threatened by other artists.”

The conflict has left some young singers in the cast, who are not yet stars like Mr. Brubaker and are just starting out in a tough environment for opera, anguished about whether to take advantage of a singing opportunity and risk the ire of colleagues, or to accept the argument that digital music is anathema to their profession and quit their hard-won jobs.