I'd like to analyse recordings to see when and how much out of tune I sing, in order to practice my singing. I'm aware of expensive solutions such as Melodyne, but is there any free way to do that?
You can download a choice of free tuner apps for any computer, tablet or phone.
I should warn you - it will be interesting to sing a slow scale and see if you're on pitch. You'll get less useful information about real-life singing. So tune your ear in by singing sustained notes into the meter, then LISTEN to your recorded voice to criticise it.