I’m working on grade 1 from the beginner course, but am unsure about one aspect.
When switching from a chord that uses more strings than the next one, how do you stop those extra strings from ringing out? For example: when switching from A major to D major the A string keeps ringing since it was open, so there was no finger lift I could’ve used to mute the string before the switch.
I know that you can normally use your thumb to mute these strings which I sometimes find myself doing, but Justin advices you to hold your thumb behind the neck as a beginner to strengthen the thumb, which I try to do as often as possible.
What options do I have left to mute the ringing open string? The right hand could be an option in theory, but it doesn’t feel practical due to the bigger movements when strumming.
Don’t worry about it.
Cleaning up your sound will come with time. It’s not so much a case of ‘learn a technique to clean it up’. More there are lots of little things that all add up.
Worry about the ones that sound bad.
In the example you give, the A string ringing out shouldn’t be too much a problem as the note A is in the D chord. Some do sound ‘off’ thought so I know where you’re coming from.
Use fretting hand to mute.
So the A to D is a tricky one, but if you touch the string in question as you are changing chords you can mute it that way. In this example I would be thinking about playing the A as a mini bar and ignoring the high e (if I was bothered about keeping the D clean). Then use the tip of the index finger (which was forming the bar) to mute. (Probably not a grade 1 friendly way though).
Use the strumming hand to mute.
You could practice using the ‘heel/side of the strumming hand to mute the A string. It takes some practice to only mute the thicker strings without touching the ones you want to play.
Overall I would suggest not worrying about it too much for now, as you progress your fingers will ‘find a way’.