Why are those compositions so popular?

ANTONÍN DVOŘÁK (1841–1904) wrote his Concerto for Cello and Orchestra in B minor, op. 104, one of his most famous works, in 1894–1895 when he was working as music director of the American National Conservatory of Music in New York. He wrote it with his friend cellist Hanuš Wihan in mind (the concerto is dedicated to Wihan), but in the end had to entrust its premiere to an English cellist, Leo Stern, because Wihan's commitments with the Czech Quartet meant that he was unable to make the date fixed for the London premiere - 19^th of March 1896. The premiere was nonetheless a sensational success, thanks both to Stern and the Philharmonic Society orchestra. It was enthusiastically taken up by other cellists and eventually Hanuš Wihan too, although he did not perform it until the 25^th of January 1899 in the Hague.

The much praised symphonic conception of the concerto, which was more than once called Dvořák's Tenth Symphony, is evident from the start in the lengthy introduction to the  romantically cantabile and intense first movement ((Allegro), in which the cello part not only  adds fullness and accent to its heroic contours, but directly helps to create them with its masterly stylisation. The second movement,  Adagio, ma non troppo, conceived as an introverted lyrical meditation, brings a sudden calm. After this the impact of the Finale. Allegro moderato is all the greater. Full of energy, brilliance and melodic warmth, this movement had been altered by Dvořák after the sudden death of his sister-in-law and one time love, Josefina Kounicová-Čermáková; the composer added a violin sonata with a quotation of the theme of his song „Leave me Alone“, which had been Josefina's favourite.

Symphony no. 4 in F minor, op. 36 by PETER ILYICH TCHAIKOVSKY (1840–1893) consists of four movements. Exceptionally, surviving letters from the composer to his friend and patroness  Nadzhezhda Filaretovna von Mekk and the composer Sergei Ivanovich Tanyeyov written immediately after the premiere of the new work on the 10^th of February 1878 offer us Tchaikovsky's own detailed commentary on the symphony. As the composer explains it, the programme of the first movement is—"roughly"—that "all life is an unbroken alternation of hard reality with swiftly passing dreams and visions of happiness ...". He goes on: "No haven exists ... Drift upon that sea until it engulfs and submerges you in its depths".   „The introduction  (1^st movement – Andante sostenuto) is the kernel of the whole sumphony, its chief thought is the fatal power (fate) which prevents one from attaining the goal of happiness...There is nothing to be done but to submit to it and lament in vain (2^nd theme of the 1^st Movement) ... Would it not be better to turn away from reality and submerge oneself in dreams? (3^rd theme of the 1^st Movement)... How distant now sounds the obsessive first theme of the allegro!  ... But no, these were just daydreams, and fate is waking me from these (reprise of the basic theme of the 1^st movement) ... The second part of the symphony (2^nd movement – Andantino in modo di canzona) expresses another phase of sadness. This is that melancholy feeling which comes in the evening when, weary from one’s toil, one sits alone...  One regrets  the past, but no longer has the desire to start to live anew...… The third part (3^rd movement – Scherzo) expresses no deinite feeling.  It is made up from capricious arabesques, of elusive images which can rush past in the imagination after drinking a little wine and feeling the first phases of intoxication. ... these are completely disparate images which rush past in the head during sleep.  The fourth part (4^th movement -  Finale). If within yourself you find no reasons for joy, then look at others. ... Learn to rejoice in the joy of the others! To live is still possible!“