It was a big week for Oscar, with two announcements on Friday of changes that might seem like minor tweaks at first glance but in fact have bigger implications.

The Academy of Motion Picture Arts & Sciences board OK’d the music branch’s recommendation to alter the best-song voting so that it’s possible there will be no nominees in any given year. It’s an apparent attempt to preserve the integrity of the category, but an example of “in order to save it, maybe we could eliminate it” thinking.

The other move was the board’s decision to present the “testimonial” awards — the Thalberg nod to filmmakers, the Jean Hersholt Humanitarian Award and the honorary Oscars for career excellence — at a black-tie event in November for 500 invited guests, rather than presenting them on the Oscarcast.

The good news is that the Academy, long accused of being too conservative, is proving that last Wednesday’s announcement (10 best-pic contenders) was no fluke. Every year the various branches, committees and the board reviews the previous awards season and debate changes, but this year, they’re making moves on a bold scale. And more changes may be in the offing.

It’s ironic that at last Wednesday’s press conference, convened to announce the 10-pic rule, AMPAS prexy Sid Ganis said more noms will not dilute the category but rather broaden the options. Yet at the same meeting, the board decided to limit another category so sharply that it’s possible there will be no award in certain years.

The music branch annually conducts a “bake-off” in which voters see clips of eligible songs as they are used in each film. The voters then rate a song on a scale of 6 to 10. Under the new ruling, if no song earns 8.25, there will be no nominations. If at least one hits that magic number, it will be nominated, as will the second-highest scorer.

(Previous rules had specified three to five nominees, and the new rules say the category will still max out at five.)

The bake-off was an earnest attempt to ensure that a song’s contribution to a film was more important than diskery sales, since pop-rock singer-songwriters have increasingly become a presence in a film’s score, much to the consternation of some music branch members.

But the bake-off limited the voting pool (you couldn’t vote without seeing these clips) and worked to the disadvantage of songs that summed up the mood and ideas of the film but were played during closing credits. (Bruce Springsteen’s “The Wrestler” was a recent example of a closing-credits song that was shut out.)

The music branch is undoubtedly sincere in its frequent attempts to rethink the rules, and this is just the latest in a long line of attempts to come up with an acceptable way of voting. However, over the weekend, several Acad members fretted that the music branch’s voting system is a bid to bring a scientific measuring stick to the unscientific realm of artistic contributions.

The question is: Who benefits from this decision? It’s hard to determine who would be happy with fewer song noms or wins.

But theoretically, the Academy and the tribute winners will benefit from the November gala.

On Friday, the Acad press release pointed out that there will not be more than one Hersholt or Thalberg in any given year, and the maximum will be four tribute awards per year. However, there could be fewer than that.

The move frees up the Academy, which had limited the number of annual honorees due to Oscarcast time considerations. The Acad honorees will be selected and announced in September.

The move will streamline the show, which hit an all-time ratings low in February 2008, while other recent telecasts have also declined as the ceremony faces increased competition from a glut of other awards shows and other entertainment options (cable, the Internet, et al.).

Recipients of the tribute awards may not be happy to be KO’d from the Oscarcast, but a dedicated ceremony will provide more time for clips and testimonials without the time constraints of the Oscar telecast.

The board had long been resistant to changing the annual rites, hampering some previous producers. But this year’s Oscarcast altered a lot of traditions and showed the board that change can be good — and it also saw a ratings bump.

Still, members of some other branches may be sweating that Friday’s two decisions, which streamline the show, may be the tip of the iceberg.

(Jon Burlingame contributed to this report.)