From April 20–23, 1989, pre-election meetings were held in Lviv for four consecutive days, drawing crowds of up to 25,000. The action included an one-hour warning strike at eight local factories and institutions. It was the first labor strike in Lviv since 1944. On May 3, a pre-election rally attracted 30,000 in Lviv. On May 7, The Memorial Society organized a mass meeting at Bykivnia, site of a mass grave of Ukrainian and Polish victims of Stalinist terror. After a march from Kiev to the site, a memorial service was staged.
Prior to the warning strike when was the last labor strike in Lviv?
1944

Back in Warsaw that year, Chopin heard Niccolò Paganini play the violin, and composed a set of variations, Souvenir de Paganini. It may have been this experience which encouraged him to commence writing his first Études, (1829–32), exploring the capacities of his own instrument. On 11 August, three weeks after completing his studies at the Warsaw Conservatory, he made his debut in Vienna. He gave two piano concerts and received many favourable reviews—in addition to some commenting (in Chopin's own words) that he was "too delicate for those accustomed to the piano-bashing of local artists". In one of these concerts, he premiered his Variations on Là ci darem la mano, Op. 2 (variations on an aria from Mozart's opera Don Giovanni) for piano and orchestra. He returned to Warsaw in September 1829, where he premiered his Piano Concerto No. 2 in F minor, Op. 21 on 17 March 1830.
Who did Chopin hear play violin in 1829 that prompted him to write a composisition?
Niccolò Paganini

Rebetiko, initially a music associated with the lower classes, later (and especially after the population exchange between Greece and Turkey) reached greater general acceptance as the rough edges of its overt subcultural character were softened and polished, sometimes to the point of unrecognizability. It was the base of the later laïkó (song of the people). The leading performers of the genre include Apostolos Kaldaras, Grigoris Bithikotsis, Stelios Kazantzidis, George Dalaras, Haris Alexiou and Glykeria.
One of the leading performers of the laiko genre is who?
Apostolos Kaldaras