Hot Cross Buns
Three notes, one string, going down. It's the first tune in a lot of method books because there's nothing to it but the bow and three fingers — and it lives entirely on the G string, so it's also your first real reading below the staff.
"Hot cross buns, hot cross buns"
How to play it
High 2, 1st finger, open G — a step down each time. All down-bows to start (lift the bow and reset at the frog between each), so every note has the same strong, clean attack. The last note is long: hold the open G for two counts and let it ring.
"One a penny, two a penny, hot cross buns"
How to play it
'One a pen-ny' — four quick open-G eighths. 'two a pen-ny' — four 1st-finger A eighths. Keep the bow completely even; the only thing that changes is one finger dropping. Then 'hot cross buns' once more to close — quarter, quarter, half. Small strokes, middle of the bow.
The whole tune
The shape is A – A – B – A: "Hot cross buns" twice, the quick "one a penny" bar, then "hot cross buns" to finish.
The one thing this tune is for
The high-2 B on the G string. It's a high 2nd finger — up against where the 3rd finger would go — not halfway between 1 and 3. Put it in the middle and you get B♭, and the tune sours on the very first note.
The usual mistake
The middle B♭ (2nd finger halfway) instead of B♮ (2nd finger forward, against the 3rd) — the tune goes sour immediately. And rushing the "one a penny" eighths — they're exactly twice the speed of the quarters, no faster; subdivide the bars before them.