We are going to skip the first question: 「Is the combination of the song and Qactus good?」
We already know the answer because of the Four Filters.
We learned that the guitar with Qactus on 2nd fret is a good match with these keys :
These Keys will change to the following 「2nd Stage, 2」 into this :
It seems like it's getting complex. Hang in there!
We learned about the keys「A」,「D」,「E」 even though it’s very tricky because we can’t skip the basic knowledge whenever we use Qactus but we are going to change into the keys 「G」,「C」,「D」. Let's stick it out and learn the QactusCore-Method!
This is the image of the keys that are a good match with Qactus referring to「2nd Stage, 2」. We learned that the key you normally play the guitar in without Qactus is different when you play the guitar with Qactus.
The good matching keys with Qactus are 「A」or「D」or「E」 when the function of transpose on the website「Lyrics & Chords」is not set「-2」(=original key).
However, these three keys will change into 「G」or「C」or「D」as a good match with Qactus if the function is set 「-2」.
We are going to try another way:
We need to try to find the key among 「A」or「D」or「E」 because all websites which are similar to Lyrics & Chords show all songs with original keys.
But when you play the guitar with Qactus, the function of transpose shoud be set「-2」, and you need to play the guitar following the material of QactusCore based on「-2」as well.（= it’s called a shape key）
You will lose your way if you try to look for the key [G]or [C]. (Fortunately, [D] will be ok because both modes have it)
Refer to this chart whenever the material on the website Lyrics & Chords is set 「-2」.
This explanation is a bit longer because it’s important. The main idea here is how we solve keys which are not a good match with Qactus.
We have many possible ways to deal with any key.
We can transpose any key into convenient keys because of transposition in music theory.
There are some situations in which one may need to transpose.
It will be ok if we think that transposition is for these two reasons (at least when we play popular music).
In the former’s case, we won’t be able to play the guitar along with the original version because it’s not the same keys between the two.
However, it will be ok if you play the guitar alone with no accompaniment. This will be a good choice for people who want to play the guitar alone (without a band).
In the latter’s case, just transpose it into convenient keys if you aren’t going to practice along with the original music track.
Any kind of key can be changed into the particular key which is a good match with Qactus.
The answer to your question is : Is the combination of the song and Qactus good? Now, the first filer of the four should be clear.
Let’s settle down for a moment to avoid things being too complicated.
We are going to try transposition between the same keys because there are so many beginners who want to practice along with original music tracks.
This part from here on is only for experts who understand musical theory. Simply, skip to next「b」if you are not at the expert level yet.