Although the opening of the text, "Quam pulchra es amica mea," is identical to that of several Marian liturgical chants, the full text of the present composition matches none of these. It is in fact a pastiche of phrases from the Song of Songs (see Table 1), equally capable of functioning as a secular motet in an amorous capacity and as a Marian devotional item (in as much as the responsories and antiphons with the same incipit contain no explicitly Marian texts, either).

Table 1: Sources of text phrases in Quam pulchra es

The attribution of this piece to "Sampson" in LonBLR 11 E.xi may well be intended to apply to the following works as well (Hec est preclarum vas and Beati omnes qui timent dominum).[1] Certainly there is no stylistic incompatibility which would preclude their having been written by a single composer; on the contrary, somewhat unusual features shared by these works support a common attribution. Chief among these is a proclivity for imitation in stacked 5ths (where the pitch levels of entries follow the cycle of 5ths, e.g., A-D-G-C at the opening of Hec est preclarum vas). Use of closely-related sequentially-treated motives (with the same texture saturating all voices) links Quam pulchra es (mm. 46-9, 88-94) and Beati omnes qui timent dominum (mm. 97-100), and all three compositions feature an unusually heavy reliance on declamation on repeated minims of the same pitch (but not set off in separate homophonic phrases, as encountered frequently in contemporaneous compositions from the French royal court).

Notes
[1] On the identity of this Sampson, see the Introduction to A Choirbook for Henry VIII and his Sisters and the Editor's Commentary to Psallite felices.