We show that pairs (X, Y ) of 1-spherical objects in A ∞ -categories, such that the morphism space Hom(X, Y ) is concentrated in degree 0, can be described by certain noncommutative orders over (possibly stacky) curves. In fact, we establish a more precise correspondence at the level of isomorphism of moduli spaces which we show to be affine schemes of finite type over Z.Thus, up to an isomorphism, the graded associative algebra Hom(X ⊕ Y, X ⊕ Y ) is determined by a linear automorphism g of the finite-dimensional space Hom 0 (X, Y ), which measures the difference between the above two pairings. More precisely, fixing trivializations of Hom 1 (X, X) and Hom 1 (Y, Y ) and a basis α 1 , . . . , α n in Hom 0 (X, Y ), we get an identification of graded associative algebraswhere S(g) = S(k n , g) is a certain (2n + 4)-dimensional algebra depending on g ∈ GL n (k) (see Sec. 1.1). Furthermore, it is easy to see that replacing g by λ · g, where λ ∈ k * , leads to an isomorphic algebra.Since X and Y were objects of a minimal A ∞ -category, we get a minimal A ∞ -structure on S(g) extending the given m 2 . Thus, the problem of describing pairs of 1-spherical objects (X, Y ) as above with Hom 0 (X, Y ) of dimension n (in this case we refer to (X, Y ) as an n-pair) fits into the framework of [26, Sec. 2.2]. As in [26] we consider the moduli space of all minimal A ∞ -structures on the family of algebras S(·) over PGL n (extending the given m 2 ). The corresponding moduli functor M ∞ (sph, n) associates to a commutative ring R the set of gauge equivalence classes of minimal R-linear A ∞ -structures on an algebra of the form S(R n , g), where g ∈ PGL n (R) (see Sec. 1.1 for the precise definition).Note that by definition, we have a natural projectionwhere we identify the affine scheme PGL n with the corresponding functor on commutative rings.In the case n = 2 we need to restrict possible elements g, so we consider the principal open subscheme PGL 2 [tr −1 ] ⊂ PGL 2 where tr(g) is invertible. We denote by M ∞ (sph, 2)[tr −1 ] ⊂ M ∞ (sph, 2) the corresponding subfunctor.Our first main result, Theorem A below, relates A ∞ -structures in M ∞ (sph, n) for n ≥ 3 (resp., M ∞ (sph, 2)[tr −1 ] for n = 2) to certain noncommutative projective schemes in the sense of [2]. Recall that for a Noetherian graded algebra R one considers the quotient-category qgr R = grmod −R/ tors of finitely generated graded R-modules by the subcategory of torsion modules (it should be viewed as the category of coherent sheaves on the corresponding noncommutative scheme).Definition 0.1.1. Let R be a commutative ring, V a finitely generated projective Rmodule, and L an invertible R-module. For g ∈ End(V ) ⊗ L we denote by End g (V ) ⊂ End(V ) the R-submodule of transformations a such that tr(ga) = 0. We define the subalgebra in End(V )[z] byWe view E(V, g) as a graded R-algebra, where deg(z) = 1.Theorem A. For n ≥ 2, let us consider the functor M f ilt (n) associating with a commutative ring R the following data: a morphism g : Spec(R) → PGL n and an isomorphism 1...