What strings did orchestras use in the mid-20th century?

Edited: February 27, 2026, 10:50 AM · All I can tell you is that Segovia/Augustine developed nylon guitar strings between 1946 and 1948 because the war had caused a shortage of gut.
AI says dominants date to 1970.

Edited: February 27, 2026, 11:37 AM · I am sort of a mid-century person. My Violin training happened in the 1960s. What I remember was that everyone used a straight steel E with metal (aluminum, silver) wrapped gut A-D-G.. Pirastro was most common. I think the first quality all-steel brand was Thomastik Spirocore. My Violist teacher switched to that. They were not popular among the classical violinists. The so-called "Russian set" was steel A &E, gut D & G. When Thomastic nylon core Dominant came out, 197_, most of players my age switched. I did not, until about 10 years later. Dominants were Not an improvement in sound quality on my violins. Of course, my experience was student/amateur USA. First-rank orchestras in Europe might be a different story.
Those recordings were analog, on wide magnetic tape. Toscanini/NBC recordings monaural recordings with a single mike, vacuum tubes instead of transistors, can have a surprising high quality. The musicians had something to do with it.

Edited: February 27, 2026, 10:57 AM · Recording history/microphone frequency response complicates the question. Apparently Dolby is 1965. That's later than I'd have guessed.
You'll also get gut conservatives in the same way that you get wooden bow conservatives.

Edited: February 27, 2026, 11:32 AM · Decidedly gut, either wrapped or unwrapped but commonly the former. The gut shortage that brought on the development of steel and nylon strings had subsided after the war ended. Many professional players did not like steel-core strings.. and still don't. In professional circles even today, it's considered very "alternative" for classical players to use steel, although it has been done successfully.

February 27, 2026, 12:10 PM · It wasn't just orchestras that had to use gut strings in the 19th and early 20th century - imagine playing the Brahms concerto! Metal-wound Pirastro Eudoxas appeared in the early 1950's and were acknowledged to be tops for at least a decade but they were very expensive and didn't last long. I was glad to be able to save a lot of lolly by switching to Dominants as soon as I heard about them.

Edited: February 27, 2026, 12:57 PM · There were holdouts with gut. Heifetz always used a gut A and D, and Toscha Seidel, whom he had tapped for out of his Mozart concerto recording orchestras, actually tried to shame him for not using a gut E. (He was moved to the back of the seconds for that.)

Otherwise, something like Pirastro with steel E, or maybe a substitute of a better A, would have been standard. I had teachers and conductors who were trained mid century and played in the NY Phil or BSO. I’m no case did I see a pure gut string, although I bet at least one of them used an unwrapped A back in conservatory.

Steel core is not out of the question. At one time I was steered to Prim, when my old instrument was feeling cranky. And that would have been more common in the USSR. Depression and postwar austerity would have had their influence in the west also, but I would guess that the Viennese were the slowest to abandon their old equipment. Have a listen to the Rose Quartet’s Op 131 to hear what sound was leading the VPO until the Anschluss.

February 27, 2026, 4:22 PM · Mid 19th century, metal wound gut-core strings (except for the E) were predominant. Mostly Pirastro Olives for the high-end crowd, because these (if carefully chosen for gauge and if the instrument was adjusted for them) gave a more focused sound and more immediate response than most other strings.

When the Dominants came along, they offered an even more focused sound and better response than the Olives, without being so finicky about string gauge and adjustment as the gut-core strings.
But they still took a while to catch on (a lot of hate was expressed about them early on), because they didn't have the familiar "fuzziness sound" that players were accustomed to, and they were best optimized by slightly different playing style.