tavis: peter yarrow has always believed music can change lives for the better as part of the iconic group, peter paul & mary. they were there 50 years ago for the march on washington. they put together a concert for sandy hook elementary survivors, teachers. he has a new album called "i'm in love with a big blue frog." let's take a look at peter paul & mary singing at their 20th anniversary concert. i'm in love with the big blue frog ♪ ♪ paul was here months ago and i have a great conversation with him as always. forever busy. the work does not stopped. the commitment is something we inherited. maryeavers, pete seeger, used to say if you seen, you have to lift me. the turning point came at the march on washington in 1953, and i remember when we were singing, people knew this song. it had been a big hit. us, andvis introduced he said, what should i say? a music groupr that will express music. we were not there to entertain. we were there to express and to join other people. get all of a sudden, a quarter million people were singing the song. ♪ if i had a hammer, i would hammer in the morni

join me next time for a conversation with musician and actor peter yarrow. that is next time. we will see you then. >> there is a saying that dr. king had that said there is always the right time to do the right thing. i just try to live my life every day by doing the right thing. we know that we are only halfway to completely eliminate hunger, and we have a lot of work to do. walmart committed $2 billion to fighting hunger in the u.s. as we work together, we can stamp hunger out. >> and by contributions to your pbs station from viewers like you. thank you. >> be more. pbs.