According to Eventide's website, the H949 was "the only piece of digital gear to grace his rig".

Used for vocals on Villains, as stated by co-producer and engineer Mark Rankin in this October 26, 2017 AudioTechnology interview.

When it came time to record Homme’s final vocals, Rankin said there were three different schools of thought: “One was the upfront, clean condenser — a Sanken CU51; a ribbon for a bit of character — an RCA 44; and sometimes an old dynamic like an Electro-Voice. The Sanken has two capsules. United had one and it was insanely good; I wanted to use it for everything. The RCA44 ribbon also sounded fantastic. United have copies that have been there since they bought them new, and they’re really well looked after. Sometimes we’d use an Electro-Voice dynamic, purposely trying to get a harder, harsh sound.”

He would put either an Eventide 910 or 949 Harmonizer in the chain. “It’s a favourite,” said Rankin. “A little bit of delay and a little bit of pitch gives that really good fake room sound.” That balance between dryness and space was pretty critical. “A lot of times we’re letting the low end of the drums or the bass be the big thing and keeping guitars small. We’d have a the 949 on the vocal a lot, and then the guitars will be out wide. If we got to the point where it felt like we needed some space, we would just send something out into the room at United and record the room. It’s like the Ocean Way plug-in on UAD. Because the rooms sounds so good, you’ll fire something out on the PA, record it back on the ambient mics and all of a sudden it works.”

Eddie Van Halen is seen with two Eventide H949 Harmonizers in his effects rack on the 5150 tour in 1986.

Mentioned on the exhaustive list present in the Syro album packaging as being one of the pieces of gear used on the recording of some song(s).

"'We didn’t know where that song was going until one afternoon when we went to record the melody and I plugged a wah-wah pedal and a Tubedriver into my 100-watt Marshall,' says Joe Satriani.

'Then, just on a whim, I said, ‘Let’s try this harmonizer.’ It was one of those Eventide 949s. The sound that came out of the speakers blew us away so much that we recorded the melody and the solo in about a half-hour and sat back and went, ‘Whoa! This is a song, man!’

'And then, of course, the Eventide broke down and we couldn’t fix it. We couldn’t do anything. We lost our tone. When we finally got it working again, we weren’t able to recreate the original effect. It just sounded different. So rather than screw up a wonderful-sounding performance that may have had a couple of glitches, we decided to just leave it, because it was just swinging.

'That wasn’t the title track of the album for quite a while. It was going to be called The Lord of Karma. It wasn’t until we finished that track and added the jet noises that we realized that ‘Surfing’ was the song that summed up the feeling of the whole album.'"

All over the record, though, is an Eventide H949 Harmonizer. That’s the main effect. Usually, on all my other records, I’m using a [Roland] Space Echo or a tape echo, but I’ve become completely infatuated with the Eventide. It’s the effect that Bowie used on [1977’s] Low—just a crazy ’80s[-ish] effect, but you can do really fucked-up, weird shit on it. All the weird, echo-y, spaced-out stuff is coming from that.

In the image, you can see that the Harmonizer is part of Lee's rig.

At 4:52 in this video with Future Music Magainze, Ulrich talks about this module saying "that Eventide stuff is classic anyway I think - I have a H3000 here as well but I think for, especially for sort of chorusing I think this is - I prefer this even - this is one of the nicest choruses I know."

According to John Carpenter's website, an Eventide H949 Harmonizer was used on the "Escape from New York" soundtrack.

Outboard gear consists of the Roland Space Echo, the Eventide 949 harmonizer, a Lexicon Prime Time, a digital reverb by Ursa Major called the Space Station and an MXR digital delay, "which is great for putting drum machines through, turning it out of phase so it makes swishy sounds in the background." Speakers are a mixed bag of Ureis, JBLs and Auratones while Ocasek can't even remember what microphones he's got. "I generally just end up using the same mike for everything. And," he laughs, "a compressor over easy. There's a couple of noise gates, an Otari half-track, and"-he pauses thoughtfully-a mood. And away I go."

From Contemporary Keyboard Magazine, July 1977:

"I have an Eventide Harmonizer, which is stereo, and an AKG stereo reverb unit"

The Harmonizer he used was either an H910 or this model, the H949.

According to an article in Circus Magazine, Jonathan Cain used the Eventide H949 Harmonizer during his time with Journey in the early 1980s.