In the period before the First World War, considered by Gál as the years of his apprenticeship, he had completed an opera, a symphony, for which in 1915 he won, out of 78 contestants, the newly created 'State Prize for Composition', and other orchestral and chamber-music works. These were for the most part 'laid aside'; even the prize-winning symphony was withdrawn before the forthcoming performance and replaced by a new composition, while virtually all of the works performed at a concert devoted entirely to his works in April 1915 at the Wiener Musikverein - they included a quintet for piano and wind instruments, a piano trio, and several vocal works - were never published. A similar fate befell a quintet for flute and string quartet (performed by the Rosé Quartet in 1915), an overture to Grillparzer's play Weh dem, der lügt, performed in 1916, and a further orchestral piece Vorspiel zu einer Tragödie ('Prelude to a Tragedy'), performed at the Konzertverein in 1917.

Some works, however, survived their composer's critical judgement. They include choral works for male and female choir from 1910-1911 (Op.11 and Op.12), the earliest of his surviving works, and the cantata Von ewiger Freude ('Of Eternal Joy') from 1912, which established his wider reputation. This work was given its first performance in a concert at the Gesellschaft der Musikfreunde in February, 1913, sung by the choir of Albine Mandyczewski and conducted by Mandyczewski himself; it was published by Universal Edition in 1916 as his Opus 1. [Note: throughout his life he only assigned an opus number to his works on publication, so that the opus numbers only coincide with the order of composition under the most favourable circumstances.] The text of this half-hour long cantata is a German poem from the baroque era, a period to which he was to return on other occasions. The work is also a first indication of Gál's love of female voices which reveals itself in many of his later works.

Surviving instrumental works of this period include the Three Sketches for piano (Op. 7), composed in 1910-11, the Five Intermezzi for string quartet (Op. 10), composed in 1914, the Piano Quartet (Op. 13) and the ever-popular 'Heurigen' Variations (Op. 9), written in July 1914, just before the outbreak of the First World War. The title refers to the 'Heurigen', Viennese wine restaurants, especially those on the edge of the Vienna Woods, where the new season's wine ('Heuriger') is served during November and December, to the accompaniment of food and music. The cheerful character of this work, a set of variations on a popular Heurigen melody, which manages to incorporate the well-known tune 'O, du lieber Augustin' for good measure, captures, if in somewhat caricatured form, the prevailing light-hearted mood in Austria on the eve of the war. Much later, Gál wrote of the origin of the work:

"Over half a century ago, a hunchbacked extemporising singer by the name of Ungrad haunted the popular wine-houses of the Viennese suburbs. If you secretly slipped him a consideration with the necessary information he would improvise humorous and not necessarily polite verses to the melody of these variations, whose object was some lady or other, and such fun-poking attentions were generally not resented. The present piece was written on the day after such an occasion, as a penitential tribute to the victim. This was in 1914, between the Austrian ultimatum to Serbia and the outbreak of the First World War, and it is documentary evidence that the youth of the time greatly underestimated the seriousness of the situation. I have unfortunately forgotten the poems of the extemporising poet; but in any case they would probably have been unprintable."

The work was not published until after the war, when it was extremely popular. As one critic remarked:

"Hans Gál's 'Variations on a Viennese Heurigen Melody' are completely carefree, real Viennese folk-music. This is the Viennese Schubert, this is Austria with its love of song and its joy in music, seeking and finding expression in heightened fashion in the 'Heurigen'." [Breslauer Zeitung, 15.1.1925]

Or again:

"The novelty of the evening: 'Variations on a Viennese Heurigen Melody' proved to be a splendid thing. Hans Gál has scored a hit." [Die Tonkunst, Berlin. 1.12.1925]