Playing "Here Comes The Sun" on Mandolin
The song is in D major, which is actually one of the friendlier keys for mandolin. Four frets, open strings ringing out where they need to. The main chords you're working with are D, A, G, and B7. That's it. You don't need to get fancy. Here's the basic progression for the first verse and chorus. I'll lay it out in standard tab notation (e.strings go top to bottom: G-D-A-E): D chord: x0232x or just strum the D-A-E strings open and fret the A string second fret. Either works. The second form sounds cleaner if you're going for that Beatles sound.
G chord: 320033. Fret the low G string third fret, D string second fret, leave A and D open, then third fret both high strings. It's a bit of a stretch but you'll get used to it. A chord: x02020. Standard open A shape. Barely any finger movement needed. B7 chord: x2122x. This is the one that catches people. It's a quick three-finger shape on the middle strings. If your ring finger can't reach the A string second fret without muting the D string next to it, practice separating those fingers independently.
I spent about three weeks struggling with the B7 to G transition. What I ended up doing was anchoring my index finger on the D string second fret first, then dropping the other fingers into place. Works every time now.
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Rhythm Pattern
Don't just strum four beats per chord. The original has a specific rhythmic feel. Try this pattern: down-down-up-up-down-up. Count it as 1-and-2-and-3-and-4-and. The emphasis is on the first downstroke and the last upstroke. That gives it the right lilt. The tempo sits around 106 BPM. If you're playing along with the record, you'll naturally lock in. If you're just tab-reading, use a metronome at 90 first, then work up. Don't rush it. Most beginners play this way too fast and it sounds rushed and messy.
Lead Line
There's a simple melodic line you can play between vocal phrases. Here it is: G string: 0-2-3-2-0 (that's open, second fret, third fret, second fret, open) D string: 2-2-0-2-2
A string: 2-0-2-0-2 This runs over the D-G-D progression during the instrumental breaks. It's not complicated but it does require clear right-hand picking. Use a pick, not fingerstyle. The mandolin sounds thin and weak without one on this tune.

Common Pitfalls
People tend to barre the D chord with all six strings. That's not how the song sounds. The original mandolin part uses open strings liberally. Mute the low E string deliberately. Let the G and D ring. Another issue: the B7 chord. A lot of tab sites show an alternative voicing higher up the neck. It's unnecessarily complicated. The open-string B7 I listed above is what you actually hear on the recording. Stick with it. The bridge section goes D-A-B7-G. That B7 hanging there in the middle is the moment most players rush. Slow it down. Hold each chord for a full measure. The song breathes because of the space between chords, not because of speed.
Where to Find Tab
I've found that the version on MandolinTabs.com is fairly accurate, though they sometimes miss the melodic fills. For the bare bones chord progression, it's solid. If you want something more complete with the lead lines included, the PDF on Songsterr has decent detail but the interactive player can be finicky with mandolin tuning. You might also check the official Beatles sheet music if you can find a mandolin arrangement, though most piano/guitar transcriptions don't account for the instrument's double-string setup. The tabs you find free online will usually have the right chords but skip the nuance. That's expected. If you're serious about getting it to sound right, use the tab as a starting point and listen to the original track while you practice. Your ears will catch the details that text can't convey.
One Thing Nobody Tells You
The song works better at a slightly lower tuning if you can manage it. Dropping to D standard (D-G-B-D-A-E) instead of the usual G-D-A-E makes the chords sound warmer and closer to the guitar-like quality of the original. It's not required. It takes some adjustment to retune and retune again when you switch back. But if you're just playing this one song for fun, it's worth the half-hour it takes to get it settled. The G string is especially noticeable. In standard tuning it rings a bit bright and nasal against the D major harmony. Drop it down and the whole thing opens up.
