This song is highly simple, which consists of not difficult chords but the reason why you would feel difficult playing this song is because there are a lot of parts where you have to pull the chords.
If you want to keep the beat when pulling the chord, Practice as you say "Uh-bbam" to yourself in your mind because you are counting the actual beats while saying "Uh" to yourself. Remember to rest at the honest beat when the chord is being pulled up.
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The Intro of this song is "I - Isus4 Progress"
Play a bar of BbMajor chord, which is the first interval of the key and play Bbsus4 for next, which is the first interval of su4 chord.
It's simple, but it's not as simple as syncopation. When you are going back to play Bb Major, do not forget to play the honest beat.
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Here is a tip to give to you.
I changed "I - Isus4" of the intro to the I-IV/5th of the verse to let you know how it sounds like. It could sound similar, but a different note itself could make sound differently
If you see IV/5th, It could refer to fifth note of the chord of IV/Base. Therefore second transposition in fourth chord is what it is.
Then, Lets talk about "Key" This song is Bb Key. Bbsus4 consists of Si"b", Mi"b", and fa. Also Eb/Bb consists of Si"b", Mi"b", and Sol. Even though you play for EbBb, it does not deteriorate the composition of Bbsus4 because It's the formation of Sol included in Bbsus4's 13th
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"I-Isus4 progress" is used a lot for Intro, pray, and speech. Likewise, "I-IV/5th", the different form of I-Isus4 is also used a lot for Intro, pray, and speech.
IV/5th chord itself is a more tensioned form, which makes richer sound than Isus4. The core significance at this point is that you do not have to switch Isus4 with IV/5th. Its more like you can play it in the different way and mood you would like to play.
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I played Intro and Verse differently to teach you how it sounds like and I showed you Isus4 in Intro part because Isus4 is the most general. Regardless of how I played, you can choose to play the intro with richer Eb/Bb sound and play the verse with Bbsus4.
You do not have to play it by book but try to improvise as much as you can.
