You can always just make ust files directly in UTAU itself, you know. It'll just be somewhat more difficult. goddamn, am I supposed to be in the same generation as these?
Other than plunderin', here's some alternatives: LMMS, which is described as an unrefined open source and free alternative to FL Studio Ardour, which, well, idk really
uhh
Those are the only free and open source ones I know of that might fit, I personally have Tracktion Waveform OEM, which is meh, it does have a functional free version for you to sniff at. Reaper can be considered some type of nagware, a lot like WinRAR without a license. This and Ardour are considered "autist" tier, which means that it's one step closer to real professional usage, so it'll require some patience and setup.
What you seem to desire is something that can play an audio file, then have a midi editor that you can plot out while syncing to the tones of the vocals, of which there are many programs, both free and nagware, that might fit.
(A tracker is therefore not recommended, since that's an entirely different way of making music.)
The first section of this resource is a list of DAWs, sorted by price. There's a lot of free and demo software you can try. You can also look for more options by searching for DAWs on google.
Before you can begin, you'll need a piece of software to do all of your musical work in. Somewhere you can have multiple tracks of audio or sequenced MIDI notes, where you can apply effects and have everything musically in time. This is a Digital...