Found the following article online, use it to answer the question: What is the name of the person who believes that the set of very spare and simple preludes in the eight Gregorian modes, published in 1859, reveal "Alkan's essential spiritual modesty"?  The Esquisses of 1861 are a set of highly varied miniatures, ranging from the tiny 18-bar no. 4, Les cloches (The Bells), to the strident tone clusters of no. 45, Les diablotins (The Imps), and closing with a further evocation of church bells in no. 49, Laus Deo (Praise God). They were preceded in publication by Alkan's deceptively titled Sonatine, Op. 61, in 'classical' format, but a work of "ruthless economy [which] although it plays for less than twenty minutes ... is in every way a major work."Two of Alkan's substantial works from this period are musical paraphrases of literary works. Salut, cendre du pauvre, Op. 45 (1856), follows a section of the poem La Mélancolie by Gabriel-Marie Legouvé; while Super flumina Babylonis, Op. 52 (1859), is a blow-by-blow recreation in music of the emotions and prophecies of Psalm 137 ("By the waters of Babylon ..."). This piece is prefaced by a French version of the psalm which is believed to be the sole remnant of Alkan's Bible translation. Alkan's lyrical side was displayed in this period by the five sets of Chants inspired by Mendelssohn, which appeared between 1857 and 1872, as well as by a number of minor pieces. Alkan's publications for organ or pédalier commenced with his Benedictus, Op. 54 (1859). In the same year he published a set of very spare and simple preludes in the eight Gregorian modes (1859, without opus number), which, in Smith's opinion, "seem to stand outside the barriers of time and space", and which he believes reveal "Alkan's essential spiritual modesty." These were followed by pieces such as the 13 Prières (Prayers), Op. 64 (1865), and the Impromptu sur le Choral de Luther "Un fort rempart est notre Dieu" , op. 69 (1866). Alkan also issued a book of 12 studies for the pedalboard alone (no opus number, 1866) and the Bombardo-carillon for pedalboard duet (four feet) of 1872.Alkan's return to the concert platform at his Petits Concerts, however, marked the end of his publications; his final work to be issued was the Toccatina, Op. 75, in 1872.
Smith