Found the following article online, use it to answer the question: Whose piece is now called the Festive Symphony?  Dissatisfied with his first large-scale orchestral work, the D major Overture of 1848, Smetana studied passages from Beethoven, Mendelssohn, Weber and Berlioz before producing his Triumphal Symphony of 1853. Though this is dismissed by Rosa Newmarch as "an epithalamium for a Habsburg Prince", Smetana's biographer Brian Large identifies much in the piece that characterises the composer's more mature works. Despite the symphony's rejection by the Court and the lukewarm reception on its premiere, Smetana did not abandon the work. It was well received in Gothenburg in 1860, and a revised version was performed in Prague in 1882, without the "triumphal" tag, under Adolf Čech. The piece is now sometimes called the Festive Symphony. Smetana's visit to Liszt at Weimar in the summer of 1857, where he heard the latter's Faust Symphony and Die Ideale, caused a material reorientation of Smetana's orchestral music. These works gave Smetana answers to many compositional problems relating to the structure of orchestral music, and suggested a means for expressing literary subjects by a synthesis between music and text, rather than by simple musical illustration. These insights enabled Smetana to write the three Gothenburg symphonic poems, (Richard III, Wallenstein's Camp and Hakon Jarl), works that transformed Smetana from a composer primarily of salon pieces to a modern neo-Romantic, capable of handling large-scale forces and demonstrating the latest musical concepts. From 1862 Smetana was largely occupied with opera and, apart from a few short pieces, did not return to purely orchestral music before beginning Má vlast in 1872. In his introduction to the Collected Edition Score, František Bartol brackets Má vlast with the opera Libuše as "direct symbols of [the] consummating national struggle". Má vlast is the first of Smetana's mature large-scale works that is independent of words, and its musical ideas are bolder than anything he had tried before. To musicologist John Clapham, the cycle presents "a cross-section of Czech...
Answer:
Smetana