The Grand Alliance (GA) was a consortium created in 1993 at the behest of the Federal Communications Commission (FCC) to develop the American digital television (SDTV, EDTV) and HDTV specification, with the aim of pooling the best work from different companies.
A thorough analysis of service area, interference characteristics, transmission robustness and system attributes would be performed to determine the "best approach."
In the end, 1080, 720 and 480-line resolutions were implemented at various aspect ratios and frame rates, with progressive and interlaced scanning (the so-called "18 formats"), together with 8-VSB modulation and Dolby AC-3 audio.
[1] Later, a story emerged that MIT had entered into an agreement with Dolby whereupon the university would be awarded a large sum if the MUSICAM system was rejected.
[2] Following a five-year lawsuit for breach of contract, MIT and its GA representative received a total of $30 million from Dolby, after the litigants reached a last-minute out-of-court settlement.