Tommy’s life spanned the heyday of the Durham Coalfield, when over two thousand miners were subject to horrendous conditions at work and home, strikes and lock-outs were commonplace. Tommy not only wrote about these conditions, but also of the lives of the miners' families. Many of his works were humorous. Armstrong wrote the great 'Wor Nannie's a Mazer', which he wrote in the Towneley Arms, Rowlands Gill and 'Stanla Market' but perhaps his best-known song is 'Durham Jail'. The song is evidently autobiographical, possibly because of his part in the strike, but allegedly the result of stealing a pair of stockings in West Stanley Co-op. he said he was 'elevated' at the time, and the way the items were displayed, they seemed to him the only bow-legged stockings he had ever seen. In his condition he couldn't resist them.
But his serious works were written in English. One such song 'The Medomsley Strike' was hailed as the greatest mining song ever written.

Though his songs were mostly too local in spirit or language, as A.L. Lloyd puts it, to spread far outside the North East, he is regarded as the bard of the Durham coalfield, and one of the most remarkable of all working-class song-writers. He was a small, bow-legged man, 'cursed with fourteen children and a bottomless thirst' as his eldest son said. Armstrong made up songs, had them cheaply printed, and hawked the sheets round the pubs at weekends at a penny each to raise beer money.

When young, Armstrong was relied upon to compose a song on any event of importance in the life of the mining community, such as a strike or a pit disaster. One such was the moving 'Trimdon Grange Disaster' (v. Philip Larkin) when 74 miners were killed in an explosion on 16 February 1882. Within a few days, Armstrong was singing his commemorative song in the local Mechanic's Hall. He no doubt felt that the dialect of the pitmen, 'pitmatic', was not appropriate here and the text is more Victorian-sententious than is usual with him. Like songs written for similar occasions, it lacks the surge of inspiration or 'holy daftness' as Armstrong himself called it:

God protect the lonely widow and raise each drooping head;
Be a father to the orphan, never let them cry for bread.
Death will pay us all a visit, they have only gone before.
We'll meet the Trimdon victims where explosions are no more.

Armstrong was aware of his responsibility and once said:

'When ye're the Pitman's poet an' looked up to for it, wey, if a disaster or a strike goos wi'oot a sang fre ye, they say: “What's wi' Tommy Armstrong? Has someone druv a spigot in him and let oot aal the inspiration?” Me aud sangs hev kept me in beer an' the floor o' the public bar has bin me stage for forty year. Aw'd drink, aw'd sing, we'd drink agen, sangs wi'oot end, amen.'

The bardic duel between Armstrong and William McGuire, a newcomer to the district, took place in the Red Roe public house in Tanfield. A few miles away the men of Oakley Colliery were on strike. The owners decided to evict strikers and they scoured the slums for layabouts to move the pitmen's furniture out into the streets. The 'Oakey evictions' was chosen as the theme for the duel. McGuire's song is forgotten but Armstrong's lives on. The last two decades of the 19th century were Armstrong's most prolific years and the strike songs reflect the high feelings of the period when the Miner's Federation was growing rapidly. The words of the songs are not revolutionary and concentrate on bread-and-butter issues. As they were sung to raise money for strikers' families, some tact was required so as not to alienate the sympathy of donors. During the great Durham strike and lock-out of 1892, Armstrong acted as 'court minstrel' to William Patterson, the miners' leader, and one of his most durable songs, 'The Durham Lock-Out' dates from this time.

Most of his songs were written in local dialect. Tommy wrote a song about the West Stanley Pit Disaster of 1909 and sold it on a penny broad sheet in aid of the stricken families. Sadly no copy of his work as ever been found. Perhaps a copy will be found in an attic in Stanley one day!
Despite his much publicised shortcomings, Tommy was truly a man of the people, and, through his pen, campaigned for the people. Tommy died penniless in Havelock Terrace, Tantobie on 30th August 1920.