Breakdown of Хотя матч был долгим, фанаты радостно пели на стадионе до ночи.
Questions & Answers about Хотя матч был долгим, фанаты радостно пели на стадионе до ночи.
Хотя introduces a concessive clause, similar to English although or even though. It sets up a contrast where the second part happens despite the first part. Но just means but and typically connects two main clauses without this strong sense of concession. You could say Матч был долгим, но фанаты радостно пели…, but Хотя матч был долгим, … sounds closer to Although the match was long, … and makes the contrast stronger and more explicit.
In past tense, Russian almost always uses был / была / было / были to say that something was something. Матч долгий without был sounds incomplete in the past; it would normally be used only in present or as a fragment (for example, in headlines or very colloquial speech). So матч был долгим is the normal full-sentence way to say the match was long.