Think for a moment of congregations that have done little or no singing of the Psalter. Because there are no assigned tones, the congregation can choose to begin with just a couple of tones and use them for an allotted period of time. Then, as they become more comfortable singing the psalms, they can venture on to other tones.
So how does a church musician or pastor go about choosing a specific tone? In that quotation above the advice is given to try and match the character of the tone with the psalm text. The tones can be divided into two groups. Those in a major key (tones A–E, I–J) can be characterized as “cheerful and bright” and would be most appropriate with psalms of praise and thanksgiving (e.g., Psalm 96, 100, 150). Psalm tones in minor keys (tones F–H, K) can be characterized as more “somber and austere” and would be more appropriate for psalms of penitence and lament (e.g., Psalm 6, 32, 42).
To start using the psalm tones, a congregation might choose one from each category, tones A–E and tones F–G. As the musician prepares for a service, a careful reading of the Psalm of the Day will reveal which of the two tones would be the most appropriate for that particular psalm.
If you have seen the LSB Altar Book, you also know that specific tones have not been assigned for the Introits and Graduals. Again, the congregation is free to choose which tones to use. If a congregation is learning how to sing the psalms, it might be helpful to use the same tone for an entire season. In choosing the tone, consider the character of that season. For example, the tone for Christmas and Epiphany would likely be a major-key tone (A–E, I–J) while the tone for Lent would be from the minor-key group of tones (F–H, K).