23 August 1989 The Baltic Chain , a peaceful political demonstration of approximately two million people who joined their hands to form a human chain spanning 675 kilometres across the three Baltic states of Estonia, Latvia, and Lithuania. The demonstration arose from Black Ribbon Day observed on 23 August to preserve the memory of the victims of mass deportations and exterminations, while promoting democratic values to reinforce peace and stability in Europe. It was part of a movement known as The Singing Revolution.
Baltic Wayarticle from Wikipedia     https://en.wikipedia.org/wiki/Baltic_Way
Black Ribbon Day, article from Wikipedia     https://en.wikipedia.org/wiki/Black_Ribbon_Day
Singing Revolution, article from Wikipedia    https://en.wikipedia.org/wiki/Singing_Revolution

SONGS FROM THE BALTIC SINGING REVOLUTION
MU ISAMAA ON MINU ARM   Many recordings on YouTube       https://www.youtube.com/results?sp=mAEB&search_query=MU+ISAMAA+ON+MINU+ARM
The Estonian Singing Revolution: An Anthem of Independence,Youtube video talk    https://www.youtube.com/watch?v=P6A4vYooRk4
ISAMAA ILU HOIELDES Many recordings on YouTube      https://www.youtube.com/results?search_query=isamaa+ilu+hoieldes


Notable protest songs associated with the Singing Revolution ,   list from Wikipedia with added links to youtube recordings
"The Baltics Are Waking Up" (Lithuanian: Bunda jau Baltija, Latvian: Atmostas Baltija, Estonian: Ärgake, Baltimaad) (LIT/LAT/EST)    https://www.youtube.com/watch?v=S3BTthay29w
"Brivibu Baltijai"[20] (LAT) ("Freedom for the Baltics")   https://www.youtube.com/results?search_query=%22Brivibu+Baltijai%22
"Dzimta valoda"[20] (LAT) ("Mother tongue")   https://www.youtube.com/results?search_query=%22Dzimta+valoda%22
OST from the rock opera "Lacplesis" (LAT) ("Bear Slayer", released 1988)   
"Manai Tautai"[20] (LAT) ("To My Nation")   https://www.youtube.com/watch?v=SdCTMiTJGQ4
"Gaismas pils"[21] (LAT) ("Castle of Light")   https://www.youtube.com/results?search_query=%22Gaismas+pils%22
"Put, Vejini!"[21] – Latvian version of a Livonian wedding folk song ("Pugõ tul") and often used in place of the national anthem during the Soviet era. (LAT) ("Blow, Winds!")    https://www.youtube.com/results?search_query=%22Put%2C+Vejini!%22
"Saule, Perkons, Daugava"[21] (LAT) ("Sun, Thunder, Daugava")https://www.youtube.com/results?search_query=%22Saule%2C+Perkons%2C+Daugava%22   
"Ei ole üksi ükski maa"[20] (EST) ("There Is No Land Alone")nbsp;  https://www.youtube.com/results?search_query=%22%22Ei+ole+%C3%BCksi+%C3%BCkski+maa%22
"Eestlane olen ja eestlaseks jään"[20] (EST) ("Estonian I Am and Estonian I Will Be")   https://www.youtube.com/results?search_query=%22Eestlane+olen+ja+eestlaseks+j%C3%A4%C3%A4n%22
"Isamaa ilu hoieldes"[20] (EST) ("Keeping the Beauty of Fatherland")   
"Sind surmani"[20] (EST) ("Until I Die")   https://www.youtube.com/results?search_query=%22Sind+surmani%22
"Mingem üles mägedele"[20] (EST) ("Let's Go up the Mountains")   https://www.youtube.com/results?search_query=%22Mingem+%C3%BCles+m%C3%A4gedele%22
"Laisve" (canonical perf. Eurika Masyte [lt]) (LIT) ("Freedom")    https://www.youtube.com/results?search_query=%22Laisve%22
"Palaimink Dieve mus" (LIT) ("God Bless Us")   https://www.youtube.com/results?search_query=%22Palaimink+Dieve+mus%22
"Del Tos Dainos" (LIT) ("For That Song")   https://www.youtube.com/results?search_query=%22Del+Tos+Dainos%22
"Pabudome ir kelkimes" (LIT) ("We Woke Up, Now Let's Get Up")   https://www.youtube.com/results?search_query=%22Pabudome+ir+kelkimes%22+
"Kokia nuostabi, Lietuva esi" (canonical perf. Kipras Mašanauskas [lt]) (LIT) ("How amazing you are, Lithuania")   https://www.youtube.com/results?search_query=%22Kokia+nuostabi%2C+Lietuva+esi%22
"Šaukiu aš tauta" (canonical perf. Vytautas Kernagis) (LIT) ("I Call the Nation")    https://www.youtube.com/results?search_query=%22%C5%A0aukiu+a%C5%A1+tauta%22+
"Tevyne dainu ir artoju" (canonical perf. Rondo) (LIT) ("Homeland of Songs and Sons of the Soil")   https://www.youtube.com/results?search_query=%22Tevyne+dainu+ir+artoju%22
"Mano mylimoji / per pasaulio sniega ..." (canonical perf. Gintare Jautakaite) (LIT) ("My Beloved/Through the Snow of the World")https://www.youtube.com/watch?v=wwy9s9us_vI
"Broli, neverk!" (LIT) ("Brother, Don't Cry")   https://www.youtube.com/results?search_query=%22Broli%2C+neverk!%22+
"Pimin bruol" (LTG) ("Remember, Brother") Latgalian awakening song.   

Revolution by Song: Choral Singing and Political Change in Estonia, article by Joseph M. Ellis and Keeley Wood from the European Network Remembrance and Solidarity     https://enrs.eu/article/revolution-by-song-choral-singing-and-political-change-in-estonia