You have two string segments of equal length. Segment 1 has linear mass density μ₁and segment 2 has linear mass density μ₂. You splice the two together and then tie the combination tautly between two posts. You've spliced in such a way that, once attached to the posts, the length of segment 1 to the left of the splice is the same as the length of segment 2 to the right of the splice. When you pluck at a particular frequency you set up a standing wave that has this pattern: nodes at the splice and where each segment is attached to its pole, plus a more nodes in

You have two string segments of equal length. Segment 1 has linear mass density μ₁and segment 2 has linear mass density μ₂. You splice the two together and then tie the combination tautly between two posts. You've spliced in such a way that, once attached to the posts, the length of segment 1 to the left of the splice is the same as the length of segment 2 to the right of the splice. When you pluck at a particular frequency you set up a standing wave that has this pattern: nodes at the splice and where each segment is attached to its pole, plus a more nodes in