Maria Wiesner studied at the Conservatory in Bratislava (1970-1976). From 1976 to 1989, she worked as a teacher in the town of Partizánske and a year in the town of Topoľčany. As teachers in music schools, they were under the surveillance of the school director and the city police because their recordings were circulated among the people. Maria Wiesner said: “Once we were called to the staffroom by the director where the district inspector of education, the head of education, the director of the police and the director of the school were waiting for us. They played our own recording on the tape recorder and they wanted us to tell them the names of all the participants. We didn’t give the names of anyone except ourselves. Then we were interrogated “why we believed such delusions” and we were threatened by being dismissed. A few days later, I was called to the director where he gave me an already written application for the termination of my employment. I didn’t agree. The next day, he gave me a letter, transferring me to another school, to Topoľčany, for ideological and political reasons. In the next school year, I commuted 20 km daily to my workplace. Besides me, another colleague of mine was transferred for the same reasons to the music school in Chynorany. Their aim was to “break up” the band so that we could not be in touch. The National Security used to follow me, at times a police car used to accompany me on my way home from work, or to our meetings up to the house of my friends. It was a very unpleasant mental pressure.”
Maria Wiesner concentrated a group of musicians around herself (Zuzana Beňačková-Sládečková, piano, percussion, Ľubica Fulková-Blahová, vocals, Alena Kvetánová-Geťková, vocals, Darina Čermanová-Hudecová, vocals, Drahomíra Fiziková-Ďuračková, vocals, Miloš Sládečka, violin, vocals, Vladimír Fulka, violin), who performed spirituals, gospel music and other types of religious music. Many of them were teachers in music schools and their activities in the field of religious music were strongly disapproved by the socialist society because teachers were supposed to educate children and young people in the “conscious spirit” of atheism. The band became known as Radostné srdce [Joyful Hearts]. Their songs included, for example: Nie vždy je slnko [There Isn’t Always Sunshine], Nebesia ti rozpovedia [The Heavens will Recount], Radosť Pánova [The Joy of the Lord], Ó, Pane [Oh, Lord], Velebím [Glorify], Ani smrť, ani anjeli [Neither Death Nor the Angels], Príď, Pane príď [Come, Lord, Come]. Their projects included children’s songs as well: Blúdila ovečka [The Lamb Went Astray], Pane Ježišu, mám jednu skrýšu [Lord Jesus, I Have a Shelter], Je to Ježiš [It is Jesus], etc. They recorded these songs on cassettes in an illegal studio in Bratislava under the titles Malý Dávid 1 [Little David 1], Malý Dávid 2 [Little David 2] etc.
Their activities attracted the attention of not only the believers but also of the official authorities in the school management, of the director, the school inspector and the regional committee of the Communist Party, who tried to mar their activities and defame the teachers. They blackmailed them that, if they continued meeting, they would be officially declared Jehovah’s Witnesses in the town. Since 1989, they have continued to perform in Partizánske. They play in public concerts, most often in Partizánske but abroad as well – in Switzerland, Germany, Austria and the Czech Republic.